Chapter 7 (Legion)

The Devil with Yellow Eyes, in the form of Lenny, questions Amy about her childhood, as well as David. The Devil with Yellow Eyes wants to know more about David's father, but also notes that Cary has left the hospital.

Oliver guides Cary to the astral plane, taking him to the ice cube. Oliver explains that the parasite that torments David is a mutant named Amahl Farouk, also known as the Shadow King. Farouk locked David inside his mind, intending to fully possess his body. Cary then recalls that his body in real life holds a device that could prevent Farouk from taking over David's body, but needs the whole team back into their respective bodies. Using Oliver's diving suit, Cary wakes up Syd from her coma in Clockworks and takes her to the astral plane to explain his plan. Syd is instructed to go back and save the team, also receiving special glasses to help differentiate reality and fantasy.

Melanie manages to reach the real world, where their bodies are stuck in time. She meets with Cary and Oliver, who does not recognize her. Trapped inside his mind in the form of a casket, David is helped by an iteration of his mind, who helps him understand his history with Farouk. David's biological father was a powerful mutant who defeated Farouk in the astral plane, making him lose his body. To protect David, his father put him in foster care, but Farouk eventually found him. Farouk intends to possess his body to get revenge at his father and eventually, conquer the world. With this knowledge, he breaks out of the corner and starts wandering throughout his mind.

Syd returns to Clockworks with the special glasses, which prevents her from seeing the hallucinations. She eventually finds Kerry, but both are attacked by Walter. Farouk in Lenny's form approaches them and mutilates Walter, who also dies in the real world. Seeing that Oliver is protecting David and Syd in the real world with a shield, Farouk leaves Clockworks to knock Oliver out and returns to Clockworks to finish killing Syd and Kerry. Oliver phases out while Walter's bullet approaches David and Syd, prompting Cary to put the device on David's head.

David breaks free from his mind in the hallucination, before the whole team returns to their respective bodies in his childhood home. David manages to catch the bullets in time with his hands, while Walter's body is mutilated like his death in Clockworks. They return to Summerland, with Cary explaining that the device will lock Farouk away inside David's mind. Melanie also discovers that Oliver has finally left the astral plane, although he still seems to not remember her. Amy also apologizes to David for not telling him about his real father. As the team intends to remove Farouk from David's mind, Division 3 agents storm Summerland and corner them, led by the interrogator. He orders his agents to kill everyone but David. Inside David's mind, Farouk is seen trapped inside a casket, the way David had been, screaming and pounding; the casket suddenly cracks.

In February 2017, it was reported that the seventh episode of the season would be titled "Chapter 7", and was to be directed by Dennie Gordon and written by co-producer Jennifer Yale. This was Yale's first writing credit, and Gordon's first directing credit.^[1]

Dan Stevens played two characters in the episode: David Haller and David's mind in the form of his body. For the latter, Stevens used his natural British accent. While working on how to differentiate both halves, Stevens suggested to series creator Noah Hawley on using his natural accent, which he accepted, with Hawley saying "I guess deep down all of our rational selves are probably British". Stevens first shot the latter's scenes, before filming David's scenes, a process he deemed "challenging".^[2]

The episode introduced the existence of Charles Xavier, David Haller's biological father, by showing his wheelchair.^[3] The crew had access to any wheelchair used in the X-Men film series, settling on the wheelchair used by James McAvoy in X-Men: Apocalypse.^[2]