As Season Two came to a close, Lucifer took care of a little problem called Mom, aka Charlotte. But now he’s facing an even greater challenge – finding out who kidnapped him, and why his angel wings are back.
After a confused Lucifer wakes up in the middle of the desert with his wings back, he recruits the help of Chloe to help figure out what happened to him and why. Upon doing their own research, they come across a crime scene that could be tied to Lucifer's kidnapping. When the Lancaster Police Department get involved, newcomer Lieutenant Marcus Pierce fails to make a great impression on everyone with his stern demeanor. The investigation goes awry when Lucifer finds himself in another compromising situation and something much darker is revealed.
After Lucifer removes his wings yet again, Linda becomes concerned that he is too focused on tracking down the Sinnerman and neglecting his own well-being. Tensions continue to rise between Lucifer and Chloe, but they realize they must put their differences aside to solve a case in which Lucifer takes a sudden interest. Once Detective Pierce's past is revealed though, everyone realizes that the Sinnerman is much more dangerous than they thought.
After talking to Lucifer and Linda, Maze realizes that she is looking for more out of life and decides to head to Canada for a tricky case. Chloe however, becomes concerned when she feels that Maze is being deceived by a scheming conman. Upon further investigation, Lucifer and Chloe make a stunning realization when they find that their target may be much closer than they thought.
When a youth counselor is found murdered, Lucifer and Chloe venture into the world of high-end reform programs to find the killer. Meanwhile, Amenadiel adjusts his lifestyle in an attempt to help Lucifer, and Chloe questions Lt. Pierce's feelings towards her.
When a food chemist is found dead, Lucifer and Chloe's investigation pits them against an unexpected face - criminal defense attorney Charlotte Richards. Everyone is caught off guard when they see her back in the precinct. As Lucifer tries to understand her return, he makes a shocking discovery that helps solve the case.
When Lucifer discovers his ex-fake-wife, Candy, has gone missing, he hightails it to Las Vegas with Ella in tow. Together, the two of them work to find her, but interesting secrets are revealed along the way that could compromise the investigation. Meanwhile, Chloe is upset that Lucifer left on her birthday, so Linda tries to lift her spirits.
A reporter seeks revenge after he discovers that Lucifer has been sleeping with his estranged wife. However, when it's revealed that Linda is the reporter's estranged wife, things get messy. Lucifer's reputation and safety are on the line, especially when a serial killer from the past resurfaces.
When a murder is connected to a celebrity dating app, Lucifer and Chloe question all they know about the world of social media in order to solve the case. Meanwhile, Ella tries to avoid Charlotte, and Amenadiel helps Linda deal with the death of her ex-husband.
Lucifer is worried when he realizes that recipients of his favors start to turn up dead. After he and Chloe investigate, they are finally brought face-to-face with the Sinnerman. Meanwhile, Detective Pierce returns to work after taking a bullet, Charlotte finds a new career and Amenadiel has a new love interest.
With the Sinnerman in custody, Lucifer is prepared to go to any length to get his devil face back. But, with another victim's life on the line, will Lucifer's conscience hinder or help? Meanwhile, Trixie is introduced to Charlotte and questions the relationship she has with her father.
In a flashback episode that takes place when Lucifer first came to LA, Amenadiel comes to retrieve his fallen brother, but is shocked when he is mugged. Amenadiel enlists Lucifer's help to track down the mugger and Lucifer, in turn, offers his assistance - but only in exchange for a favor. Meanwhile, Chloe and Dan - who are still married - investigate the murder of an MMA fighter, Aidan Scott, at the hands of the same killer who mugged Amenadiel.
After Lt. Pierce's true identity is revealed, Lucifer tries to figure out his motives. In order to earn Chloe's assistance in his investigation of Pierce, Lucifer goes above and beyond to help her solve the murder of a professional surfer. Meanwhile, Amenadiel deals with a personal health issue.
When an ecstasy cook-turned-chemistry-teacher is found murdered in a cozy Los Angeles suburb, Lucifer and Pierce must go undercover to help track down the killer. Meanwhile, Maze has a newfound attraction for someone that she used to despise and Charlotte has a revelation.
When Chloe and Lucifer's investigation into the murder of a diamond thief points to one of Ella's brothers as the main suspect, Ella is driven to prove her brother's innocence and recruits an unlikely ally. Meanwhile, Linda is upset when Charlotte comes to her for help and Detective Pierce hashes out his issues with Amenadiel.
When a best-selling novelist is murdered, Lucifer and Chloe discover that her books are based on real people from her past, and must infiltrate her high school reunion in order to catch her killer. Meanwhile, Amenadiel and Linda struggle with making their relationship public.
When a murder investigation reveals the dark side of Hollywood, Chloe puts her life on the line to protect an innocent victim. Then, Lucifer comes up with a hell-raising scheme to help Cain, but when Amenadiel and Maze get involved, things don't quite go as planned.
When a superstar singer's life is threatened, the team is thrust into the world of big-ticket stadium shows, crazed fans and divas, giving Lucifer a run for his money. Meanwhile, Charlotte tries to help Linda and Maze repair their friendship.
As Chloe and Lucifer go on the hunt for a serial killer targeting couples in love, Pierce realizes the case is connected to a murder he previously solved...in 1958. Then, Lucifer becomes upset when Pierce has a change of heart about an important decision.
When Maze is the prime suspect in a murder, Lucifer and Chloe enter the world of bounty hunting to investigate. Maze decides she wants to go back to Hell, but after Lucifer refuses, she turns to Pierce for help. Meanwhile, Charlotte's sanity is questioned when she makes a big discovery and Chloe admits she's dating someone.
Lucifer and Chloe investigate a murder during which a witness claims a winged guardian angel saved her life, causing Lucifer to become paranoid about his own actions. Meanwhile, Pierce and Chloe's relationship takes an interesting turn and Lucifer discovers something that could change everything.
When a prima ballerina is brutally murdered, Lucifer helps Chloe solve the case and attempts to keep her focus away from Pierce. Amenadiel begs Charlotte to help him with an important plan, and Maze remains devoted to a task from which Pierce asked her to back away. Then, Chloe confronts Lucifer about his meddling in her life, but as he's about to make a huge confession, he finds out something that changes everything.
When Chloe takes some time off, Lucifer is forced to work with Dan on a murder case involving a dog show. Meanwhile, Charlotte and Maze have differing ideas for Chloe's party and after a wild night, Chloe rethinks a life-changing decision.
When Lucifer and Chloe investigate the death of a woman, they discover that they may be pursuing the wrong suspect. Then, Charlotte risks her safety when she decides to take matters into her own hands, and just as Lucifer makes a huge confession, he gets a tragic phone call that changes everything.