When a 22-year-old future superstar quarterback wakes up to find a dead girl floating in his swimming pool, he turns to his friend, Lucifer, for help. Lucifer enlists Chloe to investigate the case, which leads to the world of big money sports and people who will literally kill to be number one.

When Lucifer’s mother, Charlotte, turns up at the scene of a grizzly murder pleading innocence, Lucifer is hesitant to believe her tale. Not wanting to leave her on her own, he instructs Maze to babysit her – and not to torture her, allowing him to investigate the case with Chloe.

When the man who had the final piece of the Flaming Sword is murdered and the piece goes missing, Mom joins Chloe and Lucifer on the case to track down the killer. But when Lucifer gets sidelined, Maze recruits him to help save Dr. Linda's endangered career and confronts him about the secrets he's been keeping.

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.

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.

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.

While Lucifer and Chloe search for a connection between a murdered auditor and a nudist colony, Amenadiel plays host to an unexpected visitor.