Lily and Jamie visit Forest looking for answers. Katie and Lily have an awkward chat. Lyndon wants back into Devs.
Lyndon breaks into Stewart's Winnebago and asks him to help him get his Devs job back, as he is unwilling to abandon his work on the project. Lily awakes in the Napa motel James brought her to, and after deciding they cannot run, she decides to go back to San Francisco instead to confront Forest at his house. They find him there with along with Katie, who Forest says can answer Lily's questions. Katie confirms for Lily that she and Forest are lovers and that Sergei was killed by Kenton, and explains the nature of the Devs system - a powerful computer that can show the actions of any subject in the past or future. However, the future projections cease at a certain point in time, beyond which there is only impenetrable static, due to a supposed breakdown of the laws of physics themselves. Katie tells Lily that this event is now only 21 hours away, and she believes Lily, who has been seen entering the Devs lab in the future, is the cause. Katie's deterministic view angers Lily, and she leaves with Jamie; Kenton, who had been watching them since they arrived, follows them. Lily decides to go back home, and invites Jamie to sleep in her bed where they're seen kissing