In a final attempt to provoke Cuddy into examining her true feelings for him, House announces to everyone in the main lobby of the hospital that he had sexual relations with Cuddy. Cuddy responds by confronting him in a hallway, and then firing him after he suggests that they move in together. House consults Wilson, and then goes to talk to Cuddy in her office, and she seems confused about what he said. House realizes that her reactions do not add up, and that something is wrong with his analysis of the situation. He then has a flashback to the night before when he thought he told Cuddy that he needed her help with his addiction. He suddenly confronts the reality of what has happened: he never told Cuddy he was hallucinating that night, his final words of the evening were: her "go suckle the ******* child who makes you happy"; she left the office and went home, never accompanying him to his apartment. His memory of her staying by his side while he detoxed was a hallucination, and, in fact, he spent the night popping Vicodin by himself. In reality, House and Cuddy did not have sex; House's experience was just himself walking around the house, intoxicated on the pills.
House snaps back to reality, with a hallucination of Amber saying in his ear, "So this is the story you made up about who you are. It's a nice one," to which a hallucination of Kutner adds "Too bad it isn't true."