A cop arrives at Princeton-Plainsboro euphoric and laughing after being shot during an arrest, and the team traces his symptoms through carbon monoxide poisoning and Legionnaires' disease before realizing something far worse is destroying his brain. When Foreman visits the patient's apartment and develops the same uncontrollable euphoria, House quarantines him alongside the original patient — now with two people on the same fatal trajectory and no confirmed diagnosis.

By the end of the episode, every leading theory has been disproven, the original patient is dead, and Foreman is losing his vision. This first part of a two-part arc establishes how quickly a case can invert a doctor into a patient, and sets up the stakes for Part 2 with no safety net left.

—

Part of the Explained Podcasts network. More shows:  ...