In medias res Shiroe, Naotsugu and Akatsuki find themselves ambushed by a pack of briar weasel monsters. Following a game update in the present, a confused Shiroe awakens to find himself in the District of Akihabara inside the Elder Tale MMORPG while donning his in-game avatar. He encounters other panicked players and all find themselves unable to log-out. Accessing his HUD, Shiroe quickly makes contact and teams up with his friend Naotsugu. Eventually the assassin Akatsuki joins them on account of helping her revert to a feminine avatar. The next day, Shiroe and co. meet with his friend, the Master of the Crescent Moon Alliance Guild—Marielle to compare notes on their current reality. Shiroe and co. learn that the teleportation gates across all the Japanese game districts have been rendered offline in addition to the start of a widespread guild recruitment campaign to deal with the changes of the recent "Novasphere Pioneers" update. After declining Marielle's recruitment offer, Shiroe and co. discuss the possible outcomes of an in-game death and head into the Archive Tower Forests to test the theory where they are ambushed by the pack of Briar Weasels. After some initial difficulty, they are able to overcome the ambush by naturally moving their bodies to attack rather than relying on their preset attack commands. Elsewhere, a girl called Serara makes a panicked call to Marielle while being chased by two male players as a mysterious figure looks on.
Upon dying while fighting monsters, a player revives at the Cathedral and Shiroe deduces that they are truly trapped inside the game. After another meeting with the Crescent Moon Alliance, Shiroe and co. learn of the stabilizing power balance between guilds in the District of Akihibara in addition to a rise in recent PKings. While heading back to Akihibara after a day of training Shiroe and Naotsugu anticipate an ambush from nearby PKers, forcing them into a direct confrontation. However the PKers' overconfidence quickly becomes their undoing as Shiroe and Naotsugu's team work proves to be too much for them and are quickly overpowered by the latter's high-level combinations. In desperation, the PK leader tries calling in reinforcements only to discover they have been already taken down by Akatsuki. Feigning defeat, the leader tries to attack Shiroe however Akatsuki kills him. In the aftermath, Shiroe and co. try to discern the motives of the players in the game, and he deduces that since people can survive in-game without doing anything, the string of PKings were purely for entertainment purposes. Afterwards, Shiroe receives a call from Marielle and learns that she intends to take a party on a mission to rescue their comrade Serara in the District of Susukino and asks Shiroe to take care of the guild in her absence. However, Shiroe and his friends counter by deciding to go in Marielle's stead.
While continuing on their way to the District of Susukino, Shiroe, Naotsugu and Akatsuki enter a familiar dungeon known as the Depths of Palm. As Marielle calls to check up on their progress, Shiroe surprises her at the distance they managed to cover in three days. Meanwhile in Susukino, Serara seems to be doing fine in the care of Nyanta—a player using a cat avatar who had saved her from her pursuers. While they wonder about the kind of people Shiroe and co. are, the Dark Guild, Brigandia continue looting and pillaging the district. Back in Akihabara, Marielle begins a meeting with the guild masters of Akihibara, while another mysterious guild master learns of the meeting and of Shiroe's movements. Meanwhile, Shiroe and co. cross an ancient bridge in the dungeon which suddenly starts crumbling and causes Shiroe to plummet into the lake below. As Shiroe recalls his time with the adventuring group, Debauchery Tea Party, he regains consciousness to find himself having been saved by his comrades. Eventually Shiroe and co. find themselves face to face with the dungeon's boss, a Novasphere Pioneers' creature called the Rat-maso and quickly engage and defeat it battle. Afterwards, they finally arrive at the dungeon's exit and are rewarded with a spectacular view of the sunset over the channel. Elsewhere, the guild master of Brigandia—Demikas, issues a manhunt for Serara and Nyanta.
Finally arriving in Susukino, Shiroe, Naotsugu and Akatsuki enter the district weary of an ambush by the Brigandia Guild. Meanwhile, as Demikas becomes alerted of their arrival, Shiroe meets up with Serara and Nyanta at a secret location, and shockingly discovers that his old friend Nyanta had been the one protecting Serara. Afterwards, Shiroe relays his plans with Naotsugu and Akatsuki and prepares to leave the district with Nyanta and Serara. After having waited patiently for them to exit the district, Shiroe, Nyanta and Serara are surrounded by the Brigandia guild and Shiroe taunts Demikas into a duel with Nyanta. As Nyanta's swashbuckler class inflicts severe status ailments on Demikas, he crudely calls in his guild members for aid however Naotsugu intercepts them with Anchor Howl. Eventually, Naotsugu and Nyanta's HP drops to dangerous levels and Shiroe has Serara heal them. With the healing having seemingly little effect, Naotsugu activates Castle of Stone and buys them enough delay time for Shiroe to ensnare Demikas in Thorn Bind Hostage, allowing Nyanta to defeat him. As Akatsuki marvels at their perfect timing and silent teamwork while taking down Demikas' remaining healers, Serara delivers the finishing blow to Demikas in defense of Shiroe, winning the battle. With their mission successful, Shiroe, Naotsugu and Nyanta summon three griffons and the party makes their way back to Akihibara.
Having flown far out of Brigandia's reach, the group breathes a sigh of relief and Serara can't help but be overwhelmed at the kindness Shiroe and co. showed in her rescue. The party then sets up camp and Nyanta brandishes his cooking prowess by explaining that only those with the Chef sub-class are able to manually prepare food with flavor. After a venison barbeque supper, Nyanta, Shiroe and Naotsugu explain their history as part of the legendary adventuring group—Debauchery Tea Party, which causes Akatsuki to lament her own abilities. As their journey back to Akihibara continues, Shiroe reminisces about his time spent mentoring two beginners—Tōya and Minori, just before the Apocalypse, and recalls having glimpsed them joining a guild back in Akihibara. The next day, a sudden thunderstorm forces the party to seek shelter in a nearby farming village and they meet Fedor—one of the People of the Land. After interacting with Fedor and his grandchildren, Shiroe deduces that the NPCs of this world have more human characteristics, and making themselves—the anomalies of the world. Elsewhere, Tōya and Minori along with other beginners find themselves taken advantage of by the guild who coaxed them into joining. Finally, as Tōya and the rest of his guild set out the next day, he happily notices Shiroe and co. safely back in Akihibara, but finds himself unable to meet him.
The Crescent Moon Alliance guild throws a party in their guild hall to commemorate Serara's return, in addition to keeping Nyanta's cooking methods a secret from the rest of the city. Afterwards Marielle explains to Shiroe that during his absence, Akihabara remained relatively peaceful despite an unnatural uneasiness befalling its citizens whereby no fault of their own, a social divide was established between the strong and weak guilds. Marielle also outlines that since the player level-limit was raised to 100 following the Novasphere Pioneers update, the stronger guilds such as the Black Sword Knights and Silver Sword have been leveling up using EXP pot items obtained from the Hamelin guild who had been requiting low-level players for the sole purpose of creating a monopoly on their EXP pots to the stronger guilds. Following this news, Shiroe later ponders on all of his excuses up until that point but upon running into Nyanta, realizes that he had just been using them as a means to run away from the reality of Akihabara's state of affairs—despite his friends remaining by his side. Afterwards, Shiroe calls Minori and assures her that he will save them. Filled with new resolve, Shiroe meets with Marielle, Henrietta and Shōryū the next day and asks them to aid him and his newfound guild—Log Horizon, in ending Hamelin's plot and restoring Akihabara's sense of goodwill.
Naotsugu, Shōryū and Hien begin hunting ingredient monsters in the Imperial Garden Forest while the girls, builders and cooks of the of the Crescent Moon Alliance along with Nyanta begin preparing themselves for one of Shiroe's plans. At the same time Henrietta and Shiroe task Marielle with approving an exorbitant amount of budget requests for the guild as part of Shiroe's plan to obtain his requested five million gold funding by taking advantage of the fact that the world of Elder Tale has no strict ruling on how currency should be obtained. The following day the Crescent Moon Alliance opens a food booth in the city and despite initial reluctance from the citizens, becomes an instant hit with word of their delicious food quickly spreading throughout the city. Afterwards, the stall manages to make over forty thousand gold in profit despite their sales being restricted by the total amount of citizens living in Akihabara in addition to the total number they can serve daily. Shiroe then leaves the next stage of his plan to Henrietta before he informs Minori of their progress and urges her to wait a while longer. That night, Shiroe and Nyanta meet with Soujirou Theta—master of the Caravan of the West Wind guild and former Debauchery Tea Party member and asks for his aid, which he gives to Shiroe without hesitation. Finally Shiroe beings the second stage of his plan the next day.
Following the second stage of Shiroe's plan, Marielle and Henrietta meet with Karashin—master of the Shopping Street 8 guild to discuss an agreement involving the exchange of food ingredients. Karashin tries being coy in his attempt to establish an exclusive deal with the Crescent Moon Alliance's food business. Having already anticipated this, Shiroe has Marielle and Henrietta introduce their intention of bringing in the masters of the other business venturing guilds—Michitaka and Roderic of the Marine Agency and Roderic Merchant Guild respectively—thus forcing Karashin to hurriedly accept the Alliance's proposition at a severely reduced price. Meanwhile, Minori laments all of the struggles she and Tohya faced when they became trapped within Elder Tale and that they didn't heed Shiroe's advice before it was too late, thus making them unworthy of Shiroe's rescue. Back at the meeting, Shiroe has Henrietta play a dangerous game of baiting the three guild masters into investing the remaining amount of gold under the false pretense of an extremely profitable legendary Novasphere Pioneers quest led by non other than the "Villain in Glasses" himself—Shiroe. Afterwards, Tohya relates the same feelings of undeserved rescue to Minori before the Crescent Moon Alliance and Log Horizon issue invitations to Akihibara's largest guilds for a conference to discuss the city's future.
The Round Table Conference begins as the masters of Akihibara's most influential guilds gather at the city's Guild Hall. Shiroe firstly eases that he seeks only to improve the city's living state, prompting disinterest and departure from Silver Sword's guild master—William Massachusetts. Unperturbed, Shiroe continues his explanation of the conference's formation. Elsewhere, as the Hamelin captives prepare to escape, Shiroe mentions the EXP Pot extortion campaign including Susukino's dire state with Black Sword Knights' guild master—Issac arguing the lack of laws in the world. D.D.D.'s guild master—Crusty asks of a guild's fate should they refuse the laws to which Shiroe proposes harsh sanctioning. However, Honesty's guild master—Ein along with Issac and Crusty argue of the agreement's flaw should they refuse to cooperate, with Issac even threatening war. Shiroe then plays his trump card, revealing his acquisition of the Guild Hall using the five million gold and counter blackmailing the guilds over his absolute control of their affairs. Meanwhile, as the Hamelin captives manage to escape the Hall, Minori and Tohya are unfortunately captured by Hamelin's master—Schrieder. However Shiroe's control of the Hall along with help from his friends manage to successfully blacklist all of Hamelin's members. Finally, as Shiroe makes one last pitch to the conference, Issac demands Shiroe's plan.
As the Conference continues Marielle reveals the secret behind preparing food with flavor followed by Michitaka's news of the collaborative invention of a steam engine. Shiroe then explains that by simply using one's own hands instead of the command menu, new things can be invented which in turn would start a supply and demand chain reaction and hence drive Akihibara's economic system. Shiroe then proposes the establishment of Human Rights laws that would ban the PKing, kidnapping and imprisonment of players and also allow them the freedom to join and leave guilds as they desire—further suggesting that these laws also apply to the People of the Land much to the conference's surprise. However, with Marielle's help, Shiroe convinces the conference of the People's importance and the dire need to coexist peacefully with them. Presented with an undeniable case, the guild masters unanimously decide on the Round Table Conference's formation and move on to inform the city and mark the occasion with a celebration. A week later, Shiroe secures a headquarters for Log Horizon and welcomes Tohya and Minori while at the same time, outside spies begin to infiltrate Akihabara. Elsewhere, the spies report back to Sergiatte of the League of Freedom Towns – Eastal district before being approached by a woman called Lady Lenessia.
While hunting, two People of the Land notice a strange phenomenon over the forest. Meanwhile. with Akihibara now bustling with activity, Naotsugu and Akatsuki take Tohya and Minori under their wing for training. As Shiroe also starts experimenting with his scribe subclass, Marielle starts craving to visit the beach. This gives Shiroe the idea too hold a summer training camp for new players. Afterwards, emissaries of Eastal arrive in Akihabara and invite the Round Table to a meeting and ball. Having already anticipated this, Shiroe informs Crusty that it would be a prime opportunity to learn more about the People of the Land and along with Michitaka, Henrietta, Akatsuki and Misa Takayama set off the following month. At the same time, the training camp also set off to Choushi where they end up having fun at the beach. Marielle and Minori also speak to People of the Land as part of Shiroe's suggestion that they learn as much as they can. Elsewhere, the Round Table representatives arrive at The Palace of Eternal Ice and meet with Sergiatte during the ball. As Crusty and Sergiatte begin a discussion Shiroe notes that both the adventurers and the People of the Land are weary of the other. Finally, as Princess Lenessia graces the dance with her presence, Naotsugu informs the trainees that they will head into the Forest of Lagranda dungeon for party training the next day.
As the ball continues, Sergiatte invites the Round Table representatives to participate in the dance due to the People of the Lands' expectation. However much to the group's reluctance, Crusty nominates Shiroe to participate and with help from Henrietta's bard subclass, they quickly impress the entire ball. Afterwards, Minori calls Shiroe to inform him of their dungeon training and he reminds her of his teachings. The next day, Shiroe explains that the People of the Land would compete with themselves over dealings with the Adventurers in order to obtain their fighting and technological power by putting them in the People's debt. He then proposes that they create rules to protect the Round Table when the People inevitably start approaching their guilds individually and hence has Akatsuki begin reconnaissance as preparation. Elsewhere, the training camp makes their way to the Forest of Lagranda and split up into groups, however Minori has trouble speaking her mind in a group with Tohya, Rundel Haus Code, Isuzu and Serara. Eventually the group encounters some Skeleton monsters and familiarize themselves with their teamwork. Despite their best attempts however, they are quickly overpowered by the next wave of monsters and make a tactical retreat. Back at Palace of Eternal Ice, Crusty introduces himself to Lenessia.
The Round Table Representatives find themselves with invitations to various meetings throughout the palace and they divide them amongst themselves. Shiroe will attent a dinner meeting with Count Kirino of Tsukuba and the Academic's Guild, Krusty will go to an evening party of young knights and Michitaka will attend a banquet with Lord Darte. Meanwhile, as Elissa warns Lenessia to be weary of the Adventurers, the latter recalls her previous meeting with Krusty where he uses her as a convenient shield against scrutiny from the palace folk. The next day, Lenessia witnesses the sparring session with the palace knights where Krusty craftily manipulates her into accompanying him to the evening party as a reward for defeating all the knights. Elsewhere, Akatsuki eavesdrops on two noblemen at the palace and learns of a group called the Knights of Izumo, who have apparently dissapeared. Afterwards, Krusty explains to Lenessia the freedom of the Adventurers due to their resolve as opposed to her sheltered life. Meanwhile, Touya's Party is seen fleeing from a group of Skeletons. When they've gotten away from them, Rundelhaus Cord starts complaining that even though they are at a higher level they can't seem to defeat the Skeletons. Minori tries to speak her mind, but quickly backs down again. At the beach Marielle and Shoryu notice a strange phenomenon on the ocean horizon. Back at the Ancient Palace of Eternal Ice, Lord Darte asks Michitaka to share sea faring technology with him. After Krusty and Lenessia attend the formal party, Krusty explains his interest in Lenessia by comparing her to his sister in the real world. Elsewhere, Shiroe meets with Akatsuki after his meeting with the Academic's Guild and learns of the information she gathered, when suddenly a weird phenomenon happens: everything start to vibrate and the flowers wither as the Enchanter and Assassin readied their weapons. Then suddenly a mysterious man appears, introducing himself as Ri Gan the mage from Miral Lake.
Being an academic in the study of World-class magic, Regan offers Shiroe and Akatsuki an explanation of the World Fraction spell and its thrice use in the world's history, with Shiroe correctly deducing the third time being the Apocalypse. Regan explains that 350 years ago the Human, Elf and Dwarf races destroyed the Alv kingdom out of technological jealousy. Seeking revenge, the remaining Alves cast the first World Fraction which resulted in the creation of the endlessly respawning demi-humans which pushed the planet into a world war. This caused humanity to create powerful hybrid races to aid in the war, until they were forced to cast the second World Fraction which summoned the Adventurers to their aid, some 240 years ago. As Regan also explains that Shiroe's name appeared in the world's history some 98 years ago, Shiroe confirms the events using the game's rate of time as it correlates to the real world, including the start of the open beta which brought the human-controlled Adventurers and when he began playing Elder Tale. Regan then moves on to explain his Spirit Theory which involves how revival works and that memories in the form of XP are lost during the process—a theory which Shiroe decides to withhold from the Round Table for the time being. Meanwhile, Minori finally decides to speak her mind to the training group.
Minori suggests that their group hold off on entering the dungeon until that afternoon much to the protest of Rundelhaus, and instead has them each explain their respective skills. In doing so, the group discover that their teamwork lacked cohesion. After Minori explains the basics of party combat as taught to her by Shiroe, the group enters the dungeon the next day. Armed with their new knowledge, each person assumes a clearly defined role in the party and they finally overcome the battles they were forced to retreat from previously. Back at the Palace of Eternal Ice, Shiroe starts documenting all the information he learnt from Regan and lies to Henrietta to keep her from discovering them. While pondering on what to do next, Shiroe receives a call from Minori where she gives him the progress of their training and thrilling him with the fact that Minori's group finally realized the importance of teamwork and friendship. The next day, Crusty continues to meet with Lenessia while Minori, Serara and Isuzu discuss the latter's compatibility with Rundelhaus. However that night, as Rundelhaus and Isuzu have another exchange, the latter discovers that the system strangely prevents her from adding Rundelhaus to her friend list. The next day, the training camp at the beach find themselves in a sudden attack by a massive army of Sahuagin monsters.
The camp begins encountering goblins inland while Nyanta discovers a massive goblin army approaching from the north. After pooling their knowledge, Naotsugu informs Shiroe who organizes an emergency relay conference with the Round Table. Shiroe postulates that the recent attacks are part of a quest known as "Goblin King's Return". The Adventurers then realize that they neglected quests from the People to defeat the goblins in their development of Akihabara which in turn caused the Goblin King to unite a great army. At the same time, Lenessia's father leaves to defend the town of Maihama from a goblin invasion. Afterwards, the training camp discovers a goblin raiding force marching towards the nearby town of Choushi. Meanwhile Shiroe summons Soujirou and the West Wind Brigade to the Palace of Eternal Ice to aid in its defense should it come under attack. Shiroe then informs the Round Table Representatives of his hypothesis that an in-game death induces memory loss, which Crusty verifies and shockingly reveals that he had already lost some memories of the real world. Elsewhere, the training camp makes their way to the Choushi town but they end up arriving too late. However, Minori decides that the Adventurers shouldn't wait for the People to ask for their aid, and instead, attack the goblins themselves.
Minori manages to convince Naotsugu and Nyanta to let her party begin a surprise attack against the goblin forces. Meanwhile, the Eastal Lords hold their own private conference to discuss Yamato's current predicament, including the Izumo Knight's disappearance and of sacrificing Lord Kiliva's Tsukuba City to the goblins as a possible battle strategy. Lenessia eventually overhears this information as well as the Lords' intention to use the adventurers. In the meantime, Shiroe prepares specific roles with Crusty and Michitaka for their talks with the Eastal Lords until they are finally summoned. Having predicted that the Lords would try to gather more information from them, Shiroe uses the same tactic, prompting an outburst from Kiliva stating that the adventurers have a responsibility to act. Although Michitaka violently retorts that they deserve more respect than what the League has shown them. At this time, Lenessia reluctantly makes a sudden appearance and notes the League's error in negotiating with the adventurers and instead proposes that she go to Akihabara to respectfully recruit volunteers to aid the People. Afterwards, as Minori's party continue fighting with their own resolve, Shiroe, Akatsuki, Crusty and Lenessia make their way to Akihabara as Shiroe remarks that Lenessia may be the one to change the Cities of Eastal.
Upon arriving in Akihabara, Lenessia can't help but marvel at the different culture of the city. Shiroe and Crusty organize a meeting in the middle of the city, drawing hundreds of adventurers. Wasting no time, Shiroe stirs the crowds with the threat the goblin army poses to the League of Freedom Cities, Eastal. After presenting the option that the adventurers do not have to act, Shiroe introduces Lenessia who makes a heartfelt plea for adventurers to aid her in defending Eastal. Heeding Lenessia's words, the adventurers rally behind her with Crusty and Shiroe issuing the expedition to defeat the goblins as a quest from the Round Table. Crusty then takes almost half of the adventurers, along with Lenessia to the Narashino Port while Shiroe heads to the Midraunt Equestrian Park to set up a battle headquarters. In the meantime, Sergiatte meets with Michitaka and Henrietta to explain the developing rift between the League and the Cowen family thanks to Lenessia's actions and of the power difference between the People and the adventurers, although they decide to wait for a solution from Shiroe. Elsewhere, as Lenessia ponders on the consequences of her actions, the training group makes a stand against the goblins at Choushi. Finally, after Crusty and Misa Takayama divide the adventurers into raiding parties, Crusty issues them the single order to kill all goblins.
Upon arriving on the battlefield, Crusty's group engages the goblin army in battle at the Kasumi Lake. Meanwhile, at the headquarters established at the Midraunt Equestrian Park, Shiroe explains the pivotal role the town of Choushi plays in his plan to contain the goblin advancement. At the same time, a large army of Sahuagin monsters begin moving towards Choushi and the trainees persuade Marielle to let them defend the town. While watching the trainees fight, Naotsugu and Nyanta comment on their battle styles and of Minori's attempt to imitate Shiroe's Full-Control Encounter tactic. As the battle of Choushi wears on, Minori's group takes off to defend other parts of the town while Shiroe informs Marielle of the arrival of reinforcements in another hour. With the battle taking a huge toll on them, Minori's group soon finds themselves slowly overpowered against a small group of goblins and dire wolves. As Tohya's HP reaches critical levels, Minori starts losing control of the battle. However Rundelhaus suddenly charges at the last two wolves with his magical gauntlets and kills them in a suicide attack. In the aftermath, Rundelhaus' friends try in vain to heal and revive him. Already knowing the inevitable though, Isuzu tearfully explains Rundelhaus' nature as a Person of the Land—who dies permanently. Refusing to give up, Minori immediately asks Shiroe for his aid.
Shiroe leaves for Choushi while Minori relays their situation. Using Regan's theories of revival, Shiroe has Minori, Serara and Isuzu alternate between restoring Rundelhaus' health and magic to prevent his body from being destroyed. Meanwhile, Misa and Lenessia update Crusty on the status of the battle and they prepare to intercept the goblin general's forces in Zantleaf. At the same time, Shiroe arrives at Minori and co's location and uses his enchanter abilities and a revival item to restore Roundelhaus' magic and temporarily revive him as a zombie for a few minutes. As Rundelhaus awakens and accepts his fate much to the grief of his friends, Shiroe sharply rebuffs his resolve. Using the theory to bend the laws of the world by making things oneself, Shiroe presents Rundelhaus with a contract to join Log Horizon as an adventurer. Willing to use his abilities for the good of others, Rundelhaus signs the contract and dies as one of the People of the Land. Elsewhere, Crusty and the other adventurers mercilessly slaughter the goblin general and his forces at Zantleaf while Marielle's group and the reinforcements repel the Sahuagin monsters invading Choushi. Afterwards Shiroe explains his definition of an adventurer to Minori. Finally, Rundelhaus awakens at the cathedral to his new status as an adventurer and gets a severe scolding from Isuzu for his recklessness.
A month following the battle at Zantleaf, Eastal holds a grand ball for the adventurers for their victory against the goblin general, which Shiroe includes in his plan to eventually defeat the Goblin King in Seventh Fall. At the same time, Shiroe does his best to avoid attending the ball and learns of an event called the Demon Festival of Suzaku Gate which occurred in the west of Yamato. While walking the Palace of Eternal Ice, Shiroe surprisingly listens to a mysterious woman cryptically telling a group of children the story of how he saved Rundelhaus. Afterwards Shiroe visits Regan and learns that another adventurer in the district of Minami had also used world-class magic along with the knowledge that the Izumo Knights were involved in the Demon Festival. Back at the ball, while Crusty and Lenessia dance, the latter recalls a conversation with Sergiatte where he assigns her as the Eastal ambassador to Akihabara in order to repay the adventurers. At the same time Shiroe thanks Akatsuki for her help in their previous trials with a dance. Sometime later, Lenessia moves to Akihabara to begin her ambassadorial duties and Shiroe spreads the information of the consequences of death as a rumor to suppress panic. As things return to normal in Akihabara, Marielle proposes that they hold a festival to celebrate the autumn season.
The city of Akihabara becomes much more lively than usual as the Scale Festival looms over the horizon. While detached from the city's activities, Shiroe continues his work until Henrietta suggests that he take time away to enjoy the festival with everyone. Afterwards both Minori and Akatsuki attempt to invite Shiroe to the festival's couple cake-eating contest. Minori explains to Isuzu that she intends to use the contest's reward to improve the public's trust of Shiroe which had been wavering as of late. The next day, Shiroe participates with both Akatsuki and Minori and the former receives a large amount of envy from the other participants for bringing two girls, which only escalates when Akatsuki and Minori begin competing with each other for his attention. However the trio end up failing the contest and while mulling over the day's events atop Log Horizon's headquarters, Shiroe decides to better spend his time with his guildmates. Akatsuki then joins him and they have an awkwardly brief conversation where she shows her feelings for him despite Shiroe's obliviousness. At the same time, Minori catches them and runs away with a broken heart after admitting her feelings for Shiroe to herself. However with encouragement from Tohya, Minori realizes that since she has yet to do anything about her feelings, she has no reason to be sad.
The second day of the Scale Festival gets underway and the members of Log Horizon go off on their own for the day's activities. Meanwhile, Minori stops off at Karashin's busy office to procure tickets for the Twilight Banquet and offers her services while the city's inhabitants begin getting into squabbles with merchants of the People of the Land. At the same time Minori begins to use her apprentice sub-class to help Karashin account for the festival's finances. Elsewhere Nyanta peacefully kicks a rowdy Person of the Land out of a restaurant and reports the matter to Shiroe. While the Black Sword Knights and D.D.D. guilds work on maintaining order during the festival, they resolve more disputes involving the People of the Land. Issac and Crusty then discuss Shiroe's traits and agree that he works his best when for the good of others. After putting a stop to yet another rowdy Person of the Land, Shiroe finally notices the strangeness of the People's behavior and after Minori reports inconsistencies in the festival's paperwork all resulting from errors by the People, Shiroe confirms that the city may be under attack and makes haste for the Guild Building while disgruntled at his own carelessness. Meanwhile, a vessel called the New Spirit Ship led by the sinister looking Lord Malves prepares to make contact with Akihabara.
Shiroe postulates that the People of the Land led by the newly arrived Lord Malves of Westelande to be responsible for the attack on the city, with the intention of destroying the Round Table's reputation and treaty with Eastal. In preparation to counterattack, Shiroe has his comrades provide him with more information while Minori does her best to keep Karashin's office flowing using the skills taught to her by Shiroe. Afterwards Shiroe begins plotting all the points of disturbances caused by the People of the Land but has difficulty in discerning a pattern out of their randomness until it finally dawns on him that the People are improvising on the spot. While stressed for a solution Shiroe gets a spark of genius after meeting Soujirou who had innocently beaten the cake contest with the help of his guild. In the meantime Lord Malves crashes the Twilight Banquet and corners Lenessia over his supposed mishandled cargo documents. Elsewhere, in a brilliant countermeasure, Shiroe uses the West Wind Brigade's infatuation with Soujirou as incentive for them to patrol the city and handle the disturbances. Shiroe and co. then learn of the banquet disturbance and decide to make the festival as enjoyable as possible with a fireworks display as their true counterattack. Finally, Shiroe makes an appearance at Lenessia's banquet.
Shiroe, accompanied by Crusty and Michitaka arrive at the banquet and easily counters Lord Malves' ruse with one of their own, forcing the latter to make a hasty retreat. Shiroe then excludes himself from the continuing festivities until Minori voices her concern over his actions. However Shiroe reassures her that he accepts appearing as the villain as long as he can accomplish his tasks, something which also Akatsuki berates herself for being blind to. Sometime later, Shiroe goes to meet with the contact he sent to Minami—Ōshima, although a disguised woman calling herself Dariella confronts him instead. Upon seeing through her disguise though, Shiroe forces the leader of Minami's lone guild—Nureha of Plant Hwyaden to reveal herself. Afterwards, each reveals the information they possess on the other's accomplishments, with Nureha also voicing her intention to recruit Shiroe because of a supposed past meeting of theirs. She then explains her knowledge of his research into finding a way back to the real world and bribes him with her resources and his ambivalence towards Akihibara. However Shiroe rejects Nureha's proposal, forcing her to withdraw, still with her goal to have him. Later, the Scale Festival enters its last stages and Log Horizon sits down to dinner and reassures Shiroe of their intention to help him however they can. Faced with new challenges, Shiroe issues Log Horizon their next goal of changing the world of Elder Tale. In the epilogue, Shiroe notifies Regan of his intention to leave Akihibara and Regan asks to accompany him.
The city of Akihabara remains as lively as ever and holds a sports festival while the Round Table discuss their dire financial state since the high cost of maintaining the city has all but depleted their funds. Meanwhile Crusty, Issac, Karashin and Akaneya begin an offensive against the goblin camp at Seventh Fall. Shiroe later gathers the members of Log Horizon and the Crescent Moon Alliance and due to Minami spies having infiltrated Akihabara, he partly explains his intention of leaving the city. Ten days later, Shiroe, Naotsugu and Regan meet with Kinjou of the Kunie Clan to discuss the terms of a financial agreement. However as Kinjou declines to assist the Round Table, Shiroe confirms the non-existence of the moneylender class, prompting him to reveal his intention of going straight to the source of the world's gold sealed away deep in the Depths of Palm. However before leaving, Kinjou presents Shiroe with a challenge of clearing the massive raid blocking the gold source and prove their worth to the Kunie Clan. Realizing that he cannot risk requesting combat support from the Round Table due to the spies monitoring their movements, Shiroe decides to enlist other acquaintances for help. Some time in the future, Shiroe and Akatsuki meet in another plane after having both been killed during their respective missions.
Shiroe, Naotsugu and Regan arrive in Susukino where Shiroe intends to recruit William Massachusetts and the Silver Sword guild for the raid. William wastes no time in offering aid to Shiroe but notes the lack of man-power in his guild since many of his guild members retired from large-scale raids due to a phenomenon which occurs after a player dies. Meanwhile Naotsugu and Regan search around Susukino for other recruits and stumble upon a rather self-centered player named Tetra. At the same time, Demikas barges into the Silver Sword guild seeking revenge against Shiroe but after William's threats and Tetra's ramblings, Demikas stands down and William completes the necessary twenty-four player raiding party with them both. That evening the combined party of Log Horizon, Silver Sword and Brigandia members set off for the raid, with Shiroe using the opportunity to learn more about their party members. The following day, Akatsuki continues her mission by Shiroe to guard Lenessia and has a chance encounter with a stranger in Akihabara. Meanwhile the raiding party finally arrives at the gates to the lowest level of the Depths of Palm and Demikas promises to use the opportunity to crush Shiroe's plans as part of his revenge.
The raiding party proceeds through the gates to the lowest level of The Depths of Palm and find themselves in a raid zone called "The Abyssal Shaft". Dividing themselves into four teams of six, the party battles their way through hordes of monsters to the first raid boss called Vendémiarie of the First Prison and find themselves vastly overpowered by its one-hit kills and debuffs, forcing them to retreat multiple times until finally defeating it through trial and error. After spending three weeks in the raid dungeon, and defeating two bosses, the party hits a major hurdle when they fail to encounter the other bosses in addition to running short on supplies. During a brief period of rest, William recalls the events which led him and his guild to settle in Susukino, and eventually laments dragging his guild members on large raids. At the same time, Demikas' anger towards Shiroe further increases. As Shiroe wastes little time in planning the party's next move, Naotsugu explains to Tetra of the lengths Shiroe would be willing to go to protect his home in Akihabara. Back in Akihabara, as Christmas draws nearer, the Log Horizon members discuss the new "Teachings" skill which appeared after "The Apocalypse". Meanwhile a malevolent figure threateningly watches over the city of Akihabara.
Marielle, Hienretta, Serara, Liese and Mikakage join Akatsuki in the detail to protect Lenessia. Afterwards, Akatsuki ponders on her lack of strength while Henrietta and Liese notice her discomfort. The next day, Akatsuki observes other guilds during their training sessions in order to learn the secrets behind the "Teachings" skill in an attempt to strengthen herself. The other Log Horizon members also notice her discomfort but she keeps to herself and instead sinks into self pity due to her inadequacies. Meanwhile, Lenessia explains to Elissa about the persona she had been using to feign composure with the other girls. Elsewhere, Nyanta meets with Roderic about a special request from Shiroe. The next day, Akatsuki observes a sparring session by the West Wind Brigade before being noticed by Soujirou. That evening, while the girls take Lenessia out, the latter realizes that while she may not be able to understand who the Adventurers are, she does regard them as being special. Afterwards, Akatsuki leaves the group to ponder on her uselessness to Shiroe. Meanwhile, a malevolent figure called Enheart Nelreth approaches Kyouko of the West Wind Brigade in a back alley and murders her.
Enheart Nelreth continues to wreck havoc in Akihabara and throws the city into a state of disquiet. This prompts the remaining Round Table members to impose an evacuation of the lower-leveled players to Zantleaf for their protection. Akatsuki later scours the city for Enheart while Soujirou also mobilizes the West Wind Brigade in the search. Meanwhile Kinjou meets with Lenessia and takes responsibility for the serial killings done by a rogue clan member, after he had stolen the Royal Guard armor with capabilities exceeding an Adventurer. Akatsuki eavesdrops on the conversation and decides to take action after being inspired by Lenessia's strength. The West Wind Brigade later encounters Nelreth and Soujirou rushes to the scene to protect his guild members. Soujirou puts up a fierce duel against Enheart along with Akatsuki when she makes a sudden appearance. After allowing his guild members to flee, Soujirou activates his Teachings skill and tries to pass on some knowledge of it to Akatsuki mid-battle, before Enheart takes him down. At the same time, the raiding party encounters a particularly dangerous boss and it kills Shiroe and Naotsugu. Finally, Akatsuki falls in battle against Enheart and tearfully misses Shiroe before her body vanishes.
While waiting for Akatsuki to revive with Riese on Christmas Day, Lenessia realizes that she had not truly made an effort to understand the Adventurers around her and resolves to do so. Meanwhile Akatsuki has a vision of the real world and realizes that she had simply been moving forward with her life without any particular goal in mind. Afterwards she awakens in a tranquil beach landscape and encounters Shiroe while wandering around. The two share the circumstances which lead to their deaths and both trade fragments of their memories for the chance to revive. Afterwards Akatsuki revives at the Cathedral and begs Nazuna and Riese to share their Teachings with her to stop the murderer. Meanwhile, Roderic shares new information with his guild about playing as a different gender, the geological expansion of Yamato and the effects that flavor texts have in Elder Tale, concluding that the Apocalypse isn't over. Back at the Watermaple house, Riese and the other girls decide to aid Akatsuki after helping her realize that going it alone was the wrong call. Elsewhere, while Crusty and Sansa track the goblins at Zantleaf, Sansa's weapon, "Disaster" suddenly begins acting strangely and traps her in a type of barrier. However Crusty throws her out of the way only to find himself vaporized in her place.
Riese learns of Crusty's disappearance at the hands of Misa's weapon and with him currently missing in action, Henrietta advises her to keep the information under wraps for the time being. Afterwards, Mikakage calls them to explain the worldly effects of flavor texts and Riese postulates the murderer's abilities from his Byakumaru sword's text. The next day, Nazuna puts together a group of players to begin training as part of Riese's plan to defeat the murderer, and has them share their Teachings with Akatsuki. Meanwhile, Henrietta and Riese meet with the Round Table to present all the information they have on the murderer and Riese proposes a plan involving a full raid inside Akihabara to counteract the threat on New Year's Eve. However in order for the plan to work, Riese and the others ask Lenessia to deactivate the city's magic circle, which would not only disable Nelreth's Royal Guard armor, but also disable the city's defenses—leaving her torn. With New Year's Eve drawing near, Akatsuki continues training but gets no closer to understanding the Teachings. At the same time, Lenessia decides to aid the girls in the upcoming raid. New Year's Eve finally arrives and when the full raid begins that evening, Marielle and Akatsuki encounter a deranged Nelreth before Akatsuki engages.
The Akihabara Raid begins and Akatsuki uses her new equipment provided by everyone in battle with Nelreth before fleeing with Marielle to another section of the city. Following Riese's plan, they lead Nelreth through the city where he encounters groups of two-member raiding teams strategically placed to nullify his special abilities. Meanwhile, Lenessia and Kinjou reach an agreement to disable the city's magic circle. At the same time, Akatsuki pushes herself to her limits which causes her to activate her very own Teaching skill: Shadow Lurk. This gives her a slight edge until Nelreth decommissions her katana. However Tatara Amenoma gives her a new specially reforged katana with the power to challenge Nelreth's Byakumaru. Akatsuki then manages to lure Nelreth to Riese's position, where Lenessia and Kinjou simultaneously disable the city's magic circle and leaves him vulnerable to Riese's ice attack which stops him from teleporting. Finally with the support of her comrades, Akatsuki destroys the Byakumaru, defeating Nelreth. In the aftermath, the Akihabara raiding party celebrates their victory and Shiroe calls Akatsuki to congratulate her while his raiding party prepares to once again face the boss which claimed their lives on Christmas Eve.
On Christmas Eve, the raiding party engages the boss called Luseat of the Seventh Garden in the Depths of Palm. During the battle, Luseat radically changes its attack patterns and unleashes devastating field attacks on the party. Shiroe quickly provides the the most optimal course of action and the party manages to whittle down Luseat's health by fifty percent. However they fail to notice the gates open behind them and are left in a state of shock when two more bosses—Taltaulgar of the Fourth Garden and Ibrahabra of the Third Garden—enter Luseat's zone and begin laying waste to the battlefield. Facing insurmountable odds, the raiding party loses their resolve and are wiped out. Afterwards Shiroe has a vision of his younger self, prompting reflection on his neglect to form social bonds in the real world. He later brings this inadequacy to his new reality which manifested in his inability to fully trust his comrades. This resulted in him withholding his true goals from the people around him. Accepting his flaws, he awakens in Elder Tale's fourteenth server called Mare Tranquillitatis on the Moon. He eventually encounters Akatsuki wandering around and the two share the circumstances which lead to their deaths. Finally, they trade fragments of their memories for the chance to revive once more.
The raiding party revives after their overwhelming defeat on Christmas Eve and after listening to the disheartened words of his comrades, William struggles to raise their morale. This causes him to shed light on his social ineptitude in the real world and reveals the role Elder Tale had in helping him connect and empathize with like-minded people. Desperately appealing to his comrades, William mentions how truly happy they were after awakening in the very reality they had dedicated their lives too and uses this as affirmation for not quitting the raid as a fellow gamer. However when Demikas objects to his logic, William exposes his deep regret at turning his back on the Round Table but idolized Shiroe for his perseverance in accomplishing the seemingly impossible raid which resulted in the restoration of Akihabara itself. Finally, William manages to inspire everyone when he explains that he accepted Shiroe's raiding request because at the heart of being a gamer, it was truly fun. William's heartfelt words also resonate with Shiroe so much that he wonders if he can also be the kind of guild master that inspires his guild members, and resolves to tell everyone his true purpose. Finally after a week of preparation, the raiding party moves to face the trio of bosses once more.
The raiding party charges into the boss zone and begins their assault on Luseat. With their teamwork bolstered by accepting who they are, the party manages to break through Luseat's initial mode. This temporarily immobilizes the boss and while a small group cleans up its Shadow Vanguard, the rest rush through the gates towards the other boss zones. Per Shiroe's new strategy, the party divides into groups to keep the bosses far enough away from each other to prevent their field attacks from overlapping. This allows them to better focus their attacks on Ibrahabra and Taltaulgar and gain a significant advantage. However when the Vanguard make a sudden appearance on the battlefield, Demiquas recklessly draws all the Vanguard towards himself, grabs Shiroe and lures them away from the main party further down the dungeon. After proceeding for a while, Demiquas stops and demands Shiroe to properly acknowledge him. With each finding new-found respect for the other, Shiroe acknowledges Demiquas before the latter throws him towards the Abyssal Shaft's goal and escapes with the Vanguard on his heels. Finally Shiroe proceeds through the doorway to the source of the world's gold and comes face to face with Kinjou and the raid's final boss—Uru of the Ninth Garden.
A terrified Kinjou faces Shiroe while the raiding party vanquishes Ibrahabra and turns their full attention towards Taltaulgar. Meanwhile, Kinjou explains the closely guarded secret of how the system distributes gold to monsters. Shiroe then reveals his true goal of requiring funds to purchase all the zones in Yamato, then reassigning their credentials over to the server itself in an attempt to balance the property market of the world, and in a measure of good faith—forfeits all of the Round Table's land assets. Afterwards, the raiding party celebrates their accomplishment after becoming the first to clear the Abyssal Shaft and Shiroe informs Akatsuki of his mission's success. In the aftermath, the party returns to Susukino and Shiroe brings Silver Sword up to speed on all of his experiences thus far and at the same time, feels deep regret for his mistreat of Demiquas. Afterwards, with Silver Sword opting to remain and protect Susukino, Shiroe and his friends make their way back to Akihabara. Elsewhere, the members of Plant Hwyaden discuss the intelligence obtained from their surveillance of Akihabara and of Shiroe's return to the city. Finally, Shiroe, Naotsugu and newly accepted Log Horizon member, Tetra are warmly welcomed home by their friends.
Valentine's Day arrives and the city of Akihabara once again gears up to mark the festivities. Meanwhile, Shiroe has a surprising reaction when Tetra teases him about his relationship with the former leader of the Debauchery Tea Party—Kanami. Afterwards Minori eavesdrops on Tetra as she gives Akatsuki useful information about the coconia fruit and its curious effect on a loved one if presented on Valentine's Day. Elsewhere, Shiroe and Issac discuss the current state of Akihabara and the latter reports its peaceful nature, with the combat guilds taking shifts to maintain order despite the absence of the Royal Guard and the city's magic circle. At the same time, Roderic and Ichimonjinosuke present Misa with a new prosthetic arm to replace the one she lost at Seventh Fall and they hypothesize that it may be in the same place where Krusty was taken too. As the day's events continue, Akatsuki and Minori bake a coconia cake for Shiroe. However when he eats the cake and comes under the fruit's influence, the girls find themselves unable to ask him who he prefers. Elsewhere, the true master of Plant Hwyaden—Intix, reinforces her control over Nureha with psychological abuse and reminds her of their contract to gain control of the Yamato server.
Plant Hwyaden overseers the launch of their Iron-Steel Train and former Debauchery Tea Party members—KR and Kazuhiko—discuss the travels of their former leader, Kanami. KR explains that he used a possession spell on a horse to explore the world in the hopes of gathering information after the Apocalypse, and stumbled upon Kanami and her party on the Chinese server. As they made their way eastwards to Japan, Kanami decides to intercept a horde of monsters heading towards a village much to the reluctance of the assassin Leonardo. However he eventually decides to aid the others and inspires KR to swap places with his horse and offer support. As Kanami and her other party members—Erius Hackblade and Copellia—engage the monsters, Leonardo and KR show up and separate the two sentient Genius bosses from their dragon. While Leonardo uses his speed to overwhelm the Lasphere boss, the Paps boss manages to stun Erius with the truth of his nature, however Kanami steps in and falsifies its claim. Back in the present, KR explains that he doesn't know the outcome of the battle since he died facing the dragon and revived in Minami. Finally, Plant Hwyaden launches their train to an unknown destination.
Tohya, Rundelhaus Code, Serara and Nyanta return to the Log Horizon guild hall one night after watching a performance by Isuzu at a local restaurant and they give her high praise despite her modesty. Meanwhile, Shiroe and Maryelle discuss sending the junior members on their first independent journey to obtain materials for a special magic bag essential to an adventurer. Later that night, Tohya and Isuzu discuss the importance of having a talent or sport for oneself. Isuzu also explains that when she discovered a lute instrument in the Crescent Moon Alliance, it renewed her passion for music and helped her cope with their new reality after being rescued from Hamelin. The next day, the junior party excitedly prepare for their quest while their senior guild members naturally offer their advice and worry. After stocking up on weapons and item essentials, the entire Log Horizon guild have supper that night and the junior members decide to perform in the villages they pass along the way during their journey. Shiroe also suggests that they not make contact with the senior members for help as it would be a good opportunity for them to become independent. After covering all their bases and bidding their friends farewell, the junior party sets off on their journey the next day.
While continuing their journey, the junior party takes the East Sea Road per Shiroe's suggestion as the fastest way to get to the Redstone Mountains. As they approach the next town, the party decides to further push their horse summonings until their time limit runs out, and are eventually left stranded on the roadside, forcing them to make camp. Meanwhile, Rieze describes her struggle to maintain D.D.D. in Krusty's absence and Log Horizon and the Crescent Moon Alliance pledge their aid should she require it. The following day, the junior party arrives at the town of Sazan and Rundelhaus secures them a free performance at a local inn in exchange for an overnight stay. The next day, Shiroe and Issac discuss helping the People's knights get stronger and also of D.D.D.'s destabilization. At the same time, Honesty gets an influx of new parasitic members which causes Eins to contemplate drastic measures to ensure his guild's place in the Round Table. Meanwhile the junior party intercept some People of the Land being attacked by monsters and step in to help. While initially successful, they are ambushed by a swarm of powerful spirit monsters and just as they are about to be attacked, a vampiric player calling herself Roe 2 saves them in one fell swoop, before collapsing from overexposure to sunlight.
Nureha slips out of the Plant Hwyaden train and goes for a stroll as her Dariella persona. Meanwhile, the junior party escort the People of the Land to the next town and learn of a group called the Odyssey Knights that protect the People in the Boxurt Mountains from frequent monster attacks. In the next town, the party also learns that Roe 2 had set out on a journey to change her vampire sub-class and she offers to assist them with her own summonings. Elsewhere, Maryelle struggles to come up with a theme for the Spring event while Shiroe has Nyanta and Akatsuki conduct some surveillance. Meanwhile, the Round Table begins discussing the emerging economic disparity between the citizens. Eins tries to assign blame and propose controversial countermeasures which the Table disagrees with and Shiroe reminds them of the danger to the city should they make decisions without citizen input. At the same time, the junior party makes their way through the Boxurt Mountains and end up assisting some stranded People of the Land when they encounter Dariella. Afterwards they watch as the ominous Odyssey Knights pass through the mountains with their mobile cathedral which Dariella explains helps adventurers revive anywhere, at the cost of losing a piece of themselves in the process.
In the wake of Nureha's disappearance from the train, Loreil begins a frantic search for her. Meanwhile, Izuzu and the others explain to Roe 2 and Dariella of their quest goal. As their journey continues, the party makes a stop at the Town of Safil and hold a successful concert. After the concert, Isuzu has an exchange with Rundelhaus and talks about her musician father and they also shed some light on the translation errors that the system throws up between the different languages of the People of the Land and the adventurers. Rundelhaus also explains that the People only have forty-two songs given to them by God and were truly happy to hear Isuzu's music since they are unable to create their own. He goes on to elaborate upon the endless possibilities the adventurers create for them in Akihabara and causes Isuzu to break down from not heeding the advice of her lyrics. The next day, Tohya calls Dariella out on her her odd personality and Shiroe notes the loss of contact from Nyanta. At the same time, Minori and Serara suspect the Odyssey Knight's mobile cathedral to be interfering with the telepathic network. Before they can confirm their suspicion though, they notice an incredible swarm of wyvern monsters making their way towards the town.
With the threat of the wyverns bearing down on Safil, Nyanta decides to come out of the shadows and take action. Minori, Tohya and Serara decide to take the battle away from the town, however before they have a chance to do anything, the Odyssey Knights quickly engage the monsters on the outskirts of the town. The trio then look on in horror as the battle-crazed knights manically charge at the wyverns in a state of disarray with their sole aim to be killed in battle after which they are revived by their mobile cathedral and repeat the process all over again. Meanwhile, Plant Hywaden activates their nightshade device and sends nightshade monsters into the chaos enveloping Safil. This prompts the Odyssey field commander to move the battle into the town and when Tohya questions his actions, he explains their theory that dying enough times may allow the adventurers to escape to the real world and chastises him for not doing the same. Listening to their exchange, Minori comes to the realization that like Tohya, she needs to keep pushing forward asks Roe 2 to aid them for however long that may be, and they enter the fray. Meanwhile, Nyanta begins a lone assault on the Plant Hwyaden train much to Londark's surprise.
Nyanta immediately clashes with Londark and learns that Plant Hywaden intends to trigger the war which Shiroe had once proposed as a possibility. Nyanta tries his best to reason with Londark and resonates with his understandable hatred towards having no control in his new reality. However Mizufa Trudy grotesquely silences him and proceeds to clash with an enraged Nyanta. After learning little more from Mizufa other than her warped worldview, the fight eventually forces Nyanta to go for a death blow until Kazuhiko steps in. Meanwhile, after Tohya saw through her facade, Nureha decides to end the attack on Safil in some whimsical fantasy that she might receive Shiroe's approval. Back on the train, Nyanta deduces that Kazuhiko may have been somehow corrupted by Plant Hwayden despite being a double agent for the Round Table. Nyanta then presses his former Tea Party comrade for answers and Kazuhiko responds by throwing him off the train. As the battle of Safil wages on, the junior party do what they can to help and Isuzu has some self-reflection on her own experiences and how her music can help the world. Eventually, Isuzu and the others race back to Tohya, and when the Odyssey Knights' worldview brings Isuzu to tears, she performs a song to highlight her hope for the world.
Nyanta informs Shiroe of his recent encounter with Kazuhiko and of the wyvern attack on Safil which leaves the town in ruins. Dariella and Roe 2 then part ways with the junior party and the latter entrusts Minori with a letter for Shiroe. Afterwards, Tohya and the others decide to help the townsfolk with their repairs however Rundelhaus manages to convince them that they should leave the town. Back in Akihabara, Naotsugu begins to notice the return of the apathetic phenomenon which had engulfed the adventurers at the start of the Apocalypse. Shiroe also begins pondering the factors which may drive the world into a war. Meanwhile, the Brigade of the West Wind encounter a strange Person of the Land with a Genius sub-class seducing girls around the city. Back in Safil, Isuzu overhears some People of the Land voice their disappointment in their expectation of the Odyssey Knights, but feels a sense of fulfillment that she was able to briefly give them a new song. While leaving the town however, the junior party notice the People singing Isuzu's song which instils a new-found sense of hope in the world. Afterwards, Nyanta shows up and takes the party back to Akihabara and they celebrate the end of their quest with their seniors. Finally, Shiroe opens the letter from Roe 2.
Shiroe sifts through the documents sent by Roe 2 and learns new information about the world. Afterwards he pays a visit to the Brigade of the West Wind and asks of their encounter with the Genius monster. The Round Table gather some time later and discuss additional encounters with three more Genius monsters around the city. Afterwards Karashin stops off in Maihama and brings Isaac up to speed with the Round Table's latest meeting. At the same time, Nyanta and Shiroe take note of the empathetic adventurers who have lost the resolve to continue. However thanks to Serara, Nyanta realizes that the younger adventurers can still be optimistic about their futures. The following night, Shiroe lays out his hypothesis about their current reality to the senior Log Horizon members, and reveals the information sent to him by Roe 2. Roe 2 explains that she is an artificial being created by an alien race that was sent to search other universes for a resource called "empathions". She then warns them of the Genius monsters who will obtain empathions at any cost. Finally, Shiroe decides to trust her words when she explains that her companions on the Moon may be able to assist the adventurers in returning to their own reality.
Roderic informs Shiroe that a device to communicate with the Moon would cost an astronomical amount of funds to construct but he isn't sure whether it would actually work or not. Elsewhere Tohya and his party discuss whether or not they want to return to their own reality. Back in Maihama, Lord Sergiatte summons Isaac and explains that he intends to announce Iselus as the next heir to the Cowen throne and asks Isaac to continue to watching over him. Karashin later notes on the growing tensions between Westelande and Eastal. The next day, Maihama hosts a banquet for Prince Iselus and Sergiatte expresses his regret for making him bear the enormous responsibility of ruler. Though, with Isaac's support, Sergiatte presents Iselus as the heir to the throne of Maihama. A group of Westelande Landers then crash the event and attempt to assassinate Prince Iselus, however Isaac protects him with support from Karashin and Reserick. Regan later visits Shiroe to relay his latest findings and also notes that he detected a faint signal from the Shibuya TV station while investigating the transport gates. Suddenly, they receive word of people mysteriously collapsing all over Maihama and Akihabara while a mysterious black cloud showers the city of Akihabara with strange spores.
At moonrise, the player cities of Akihabara, Susukino and Minami are all simultaneously attacked by swarms of Eternal Moth monsters, whose scales rain down and knock people into a state of sleep by draining their magic points. The Brigade of the West Wind soon discover the moths' nest located in a new raid zone in the Shibuya broadcast building and the Round Table postulate that the monsters had been drawn to the broadcasting antenna from the Moon. Filled with uncertainty, Shiroe decides to put together a raiding party and makes the difficult choice of destroying the antenna. The raiding party then fights their way through Shibuya and manage to enter the raid zone in the broadcast building. However Shiroe's uncertainty hinders his strategic insight and allows the sheer volume of monsters to overwhelm the party from all angles, forcing them to make a hasty retreat. Shiroe then uncharacteristically apologizes to the party for his lack of focus, but Minori and the others dispel his uncertainty about returning home when they collectively decide to stay and help the world of Elder Tale. Finally, when Ichimonjinosuke discovers the raid boss at the top of the building, Shiroe's restored resolve helps him formulate a new plan of attack.
The Shibuya raiding party begins another assault on the Calling Fortress and manage to break through to the roof where they encounter the raid boss: Taliktan, the Genius of Summoning. After failing to establish communication with the monster, it summons swarms of moths which engulf Shibuya and the other player cities. This puts a severe strain on the antenna and Shiroe has the party take the battle into the concert hall below. Despite inflicting a great amount of damage to Taliktan, they are still pummeled by its powerful field attacks. However Shiroe's Full-Control Encounter raises the stakes and gives the party a significant advantage in pushing Taliktan to the edge and ultimately their victory. In the aftermath, Regan sets up the radio equipment and much everyone's surprise, Shiroe makes contact with Kanami in the Chinese server. She then tasks him with seeking a way to allow transit between the real and Elder Tale worlds and relieves the Shibuya party about Krusty's whereabouts. Meanwhile, Nureha and Plant Hwyaden decide to establish relations with Eastal and the Round Table to combat the common Genius threat. Finally, Log Horizon makes plans to celebrate their victory and with the dawn over the horizon, Shiroe and Akatsuki praise each other. In the epilogue, Log Horizon holds a victory party and Regan skips out on his task with repairing the radio equipment to join the festivities.