David considers whether the voices he hears might be real.
David Haller is under interrogation by government officials who believe that he may be the most powerful Mutant in existence. David is unaware of his powers, and tells the officials that he has been diagnosed as schizophrenic. Because of this, he had a troubled upbringing, eventually leading to his attempting to commit suicide. David is finally remanded to Clockworks Psychiatric Hospital. Six years after, on his birthday, he is visited by his sister, Amy Haller. She sees an improvement in him, while David is just waiting for something to happen.
David spends his days in therapy and with his friend, Lenny Busker. Sydney Barrett, a new patient, arrives at Clockworks at David is immediately smitten. She does not like being touched, but eventually agrees to be David's girlfriend and they spend all their time together. After a while, Syd is discharged from hospital and in a moment of spontaneity, David kisses her. The physical contact triggers Syd's Mutant power to switch bodies. In David's body, Syd is unable to control his powers. Causing chaos and altering reality, she causes several deaths, including Lenny who is phased into a wall. David, in Syd's body, escapes the hospital. Syd's power soon wears off, and David finds himself back in his own body, but still free from the hospital. He becomes aware that he is being followed by two people, and in his attempt to escape, is captured by the government. David is eventually rescued by Mutants Ptonomy Wallace and Kerry Loudermilk, who already rescued Syd after the incident at the hospital. Reaching a boat on the beach, David meets Melanie Bird and heads to safety.
- The Devil With The Yellow Eyes appears as one of David's toys in the opening montage.
- Several characters refer to an "incident at Red Hook." Red Hook is the name of the town next to Bard College, where Marvel character Jean Grey was buried. Jean Grey's father was a professor at Bard College and Jean Grey grew up in the area. 
- To depict David Haller losing control of his abilities in a kitchen, actor Dan Stevens was filmed separately from the practical effects, with the images layered together to create the final, slow-motion sequence. 
- During the episode there are various people that only David can see, such as: the old couple when talking to his sister, and the man in the greenery when he's sitting with Lenny. These are not actually delusions and are, in fact, some of David's personalities. 
- When Syd and David switch bodies, she is able to tap into the powers on one of his personalities. Known as Personality #5 in the comics, Personality #5 is a godlike mutant who describes himself as "The One True Legion". He has the ability to warp both time and reality which would explain how Syd was able to change the structure of the patients rooms, leaving no doors, as well as, trapping Lenny in the wall. 
- David is seen in a wheelchair early on in the episode in the hospital. This is a reference to his father in the comics, Professor Xavier.