After years of imprisonment in Asgard, Loki escapes to Earth to gain his revenge on his half-brother, Thor. Once there, Loki learns that Thor lives among humans as one of them, Dr. Donald Blake.
In this first episode we find out the origin of Prince Namor, the Sub-Mariner. Having incurred amnesia because of an illness, Namor looks for his identity on land and finds the mysterious Mrs."B", who knows & holds the real truth of his past.
A quick recap of how Steve Rogers became Captain America. Captain America's main focus is on saboteurs as he keeps his identity secret disguised as an army private. The Captain later learns that the Red Skull is behind the sabotage.
Bruce Banner becomes the Hulk by saving Rick Jones from a gamma bomb explosion. The Gorgon comes to America and fights the Hulk, only to be cured of his ugly disease by Hulk.
While Tony Stark is busy with his new race car one of his scientists plots to destroy him.
Loki enhances the mental powers of Sandu, a carnival mystic. Sandu then uses his supernatural powers of levitation to battle Thor and to trap him beneath an entire building.
Prince Namor encounters dangers and traps in his quest for the fabled Trident of Neptune. Evil Krang tries his best to stumble the Sub-Mariner as Lady Dorma pines for her beloved Prince.
Captain America is captured by his enemy, the Red Skull, who brainwashes him and hopes to use him as an assassin.
After the army shoots down their UFO, the evil Toadmen seek refuge in an underground tunnel and magnetically pull the moon toward earth, causing great disasters. Banner escapes imprisonment, confronts the Toadmen's attack and saves earth.
The Mandarin attacks Tony Stark's house but Pepper and others suspect Iron Man may be to blame.
Hoping to break up the love between Thor and Jane Foster, Odin heeds advice from Loki. Loki uses this opportunity to pit the Enchantress, the Executioner and two powerful giants against Thor.
The evil warlord Krang schemes to destroy Prince Namor so he can wage war on the surface world.
While Steve Rogers is deployed on a military mission, Bucky gets kidnapped by an evil scientist.
The Leader, a mutated super villain, learns that Doctor Banner's newest nuclear device is being transported to another military base by a train, and sends one of his Humanoids to attack the train and steal the invention.
Tony Stark is held prisoner by the Mandarin, whose latest minion is the giant android Ultimo.
Loki brings Jane Foster to Asgard and tries to convince Odin that it was Thor who brought her there. In order to prove which of his sons is lying, Odin sends both to Skornheim, where they must endure its deadly dangers.
Attuma steals the sacred trident of Neptune and kidnaps Vashti. Namor follows but it's just a distraction so Attuma's armies can attack Atlantis.
Feeling depressed over Bucky's death, Captain America decides to get revenge against Zemo.
Bruce Banner is hunted by the military for a crime he did not commit and The Hulk must fight for his justice.
The Mandarin seeks to sabotage Tony Stark's missiles. Can Iron Man manage to stop him?
Escaped convict Crusher Creel is given power by Loki to absorb the properties of anything that he touches. As the Absorbing Man, Creel uses his fantastic strength to battle Thor.
Attuma's plot to attack Atlantis is side tracked by a strange invader.
The Mighty Avengers find Captain America floating in the ocean alive after having been assumed dead for 20 years.
Banner is in custody and gets word to Rick Jones, who shows up in the army to save Banner. Rick is wounded in battle, but the Hulk saves his life.
The world's greatest expert on electricity devises a robot to destroy Iron Man.
Loki lures a hunter into The Temple of Darkness, a hidden tomb where the hunter's spirit enters the body of the Indestructible Destroyer, an enchanted suit of armor forged by Odin.
Byrrah attempts to disgrace Namor and then challenges him to a duel of strengths.
Surprised to learn that Captain America is still alive, Zemo plots an all out attack.
The Leader dispatches the Chameleon to retrieve a sample of Bruce Banner's technology.
The story of how an Archer wants to become a hero after watching Iron Man saving some people and how he is tricked by Black Widow.
Scientist Paul Duval gains the power to turn himself (and whoever he touches) into living stone. As the Grey Gargoyle, he attacks Thor hoping to steal Thor's magic hammer, which he believes will help him gain immortality.
While Namor is on the surface dealing with scientists who are drilling into Atlantis, The Behemoth attacks his home.
A Jarvis clone infiltrates Avengers headquarters and wreaks havoc.
The Leader lures Bruce Banner to his Italian villa. There, he tries to recruit the Hulk into his fold.
While Tony Stark struggles to repair the device that makes his heart work, Titanium Man challenges Iron Man to a battle on neutral ground.
Calvin Zabo, an employee fired by Donald Blake for stealing, vows revenge and uses a chemical formula to turn himself into the super powered Mr. Hyde.
The citizens of Atlantis are turning to stone. Namor must walk across lava and touch the sacred trident if he hopes to save them.
A mysterious sword wielding man breaks into Avengers headquarters and demands to be allowed to join. After the heroes defeat him, he concocts a plan to kidnap Captain America.
The Hulk is displaced by the Space Phantom, causing the breakup of the Avengers. The Avengers unite to fight the Phantom, but Hulk leaves the group, disgruntled by their attitude toward him.
The earth starts swallowing buildings and the government thinks Tony Stark's new earth digger is responsible until Stark's factory is swallowed along with Iron Man.
Thor's nemesis Loki forges an alliance with supervillains Mr Hyde and the Cobra. The trio kidnap Jane Foster to lure Thor into a booby-trap.
When an evil siren gets bored, she plots to make Namor her husband.
The Enchantress casts a spell of evil causing the Avengers to argue with each other while she launches an attack.
When the Metal Master invades the earth, a slightly mutated Hulk must use Bruce Banner's intellect to defeat him with a plastic "super weapon".
When the press discovers that Tony Stark is Iron Man, Happy puts on the armor to fool them. He quickly gets kidnapped by The Mandarin and Tony must make new armor to save him.
Zarrko, the Tomorrow Man, travels back in time to 1962 to steal a cobalt bomb that he plans on using to make himself ruler of the 23rd century. Thor follows him forward to 2262 in order to defeat him.
A ship's captain concocts a liquid to subdue the people of Atlantis while he steals the gold condinium under their streets. Namor must get the help of Dr. Debrik if he is to wake his people.
Captain America leads the Avengers into Sin-Cong to answer a distress call, only to find it's a trap set by the nation's superhuman leader, the Commissar.
The Circus of Crime is in town and is looking to rob everyone blind. Unfortunately, they try to rob Rick Jones, a friend of the Hulk.
Tony Stark creates a new laser device that quickly becomes the target of evil doers everywhere.
When the Greek god Hercules arrives on Earth, he takes a fancy towards Thor's love Jane Foster. An enraged Thor fights it out with Hercules all over New York City.
While investigating mysterious rays that are threatening Atlantis, Namor is abducted and taken to a distant planet.
Twenty years after his death, the Red Skull's sleepers awake, leaving a path of destruction across the European countryside.
The Hulk gets drawn into a subterranean war by the underground warlord Tyrannus.
When Happy is injured in a car wreck, the villainous Black Knight abducts him from the hospital and uses him as bait to lure Iron Man to his castle-fortress.
Tricked into signing a contract to become the ruler of the underworld, Hercules must rely upon Thor to champion his cause and help him to win his freedom.
Dr. Doom uses his high frequency emotion charger to make every villain attack the Peace Day festivities.
Captain America encounters a girl from his past and quickly discovers she is an agent of SHIELD who is working with Batroc.
General Ross transports Banner into the future with a T-Gun, where he fights a futuristic army and faces a godlike executioner. Rick Jones tells Talbot that Bruce Banner is the Hulk.
Upset about Pepper's love for Tony and Tony hogging the spotlight, Happy quits and goes to Ireland. Iron Man tries to convince him to return while being randomly attacked by old enemies he believed were dead.
When a race of underground lava men threaten the surface world with destruction, Thor gathers his Avenger teammates in an attempt to thwart the attack. The group is aided by an unlikely ally, their former team member, the Incredible Hulk.
Zantor captures Namor and transports him to Nero's Rome to fight for his life.
Captain America is startled to learn his old enemy, the Red Skull, is still alive. The Skull seeks the all-powerful Cosmic Cube.
Boomerang tries to steal a missile from General Ross' base and kidnaps Betty along the way, only to give her to the Hulk after a fight. Boomerang attacks an army base, but Talbot stops him. Will the Hulk ever be a hero?
While preparing for a trip to Washington DC to testify before congress, Tony Stark is kidnapped by The Thinker.