Contains spoilers for this episode and earlier episodes.
Elliot conceals his counterpart's body and prepares to take his place at the wedding. A version of Dom stops him, and he escapes towards Coney Island, where the expected ceremony falls apart. Mr. Robot tells him that Whiterose did not create this world. It is a fantasy designed to keep the real Elliot safe and trapped. The Elliot who has been fighting the Deus Group is another personality, the Mastermind, who took control and forgot his own identity. A manifestation of Krista explains how Elliot's personalities developed and why Darlene was excluded from this imagined life: her connection to her brother could bring him back to reality.
The Mastermind resists giving up control, then wakes in hospital with Darlene beside him. She confirms that he stopped the meltdown, although an explosion still destroyed Whiterose's machine. Whiterose is dead, and the friends they lost have not returned. Darlene also confirms that their work together happened and admits she knew he was different from the brother she grew up with. She stayed close because she wanted to rebuild their relationship. The Mastermind realises that the safe world he created cannot give Elliot everything while Darlene remains outside it. He accepts that he is part of Elliot and joins the other personalities, relinquishing control. Elliot opens his eyes to find Darlene waiting, and she greets her brother.