Derailed: [s1e9]

Egged on by a delusion he calls "Leo," Bryar becomes convinced that the U.S. government is monitoring him via an implanted microchip. After witnessing a police officer (present because of a suicide on the tracks ahead) speaking with Elle, Bryar snaps, kills the officer, and takes the entire train car hostage using Elle’s service weapon.

: Bryar’s own psychiatrist, who was traveling with him to a conference to present him as a success story for treating severe psychosis. [S1E9] Derailed

: A seemingly meek man who is actually carrying a gun with the intent to kill his estranged wife in Dallas. The Negotiation: Playing Into the Delusion Egged on by a delusion he calls "Leo,"

: Fans often cite this as a pivotal Reid episode. It provides the first subtle hints of Reid’s personal familiarity with schizophrenia, a theme that becomes central to his character arc later in the series. : Bryar’s own psychiatrist, who was traveling with

The situation reaches a boiling point when Josh Patel's unhelpful assistance makes Bryar even more unstable, leading Bryar to shoot Dr. Deaton. In the final confrontation, Reid manages to communicate with Bryar on a psychological level, pretending to see the "strings" of the universe as Bryar does—a reference to Bryar's expertise in M-theory . The crisis is ultimately resolved when Harold Anderson, the "Chekhov's Gunman" of the car, shoots Bryar, allowing the authorities to take him into custody.

The episode begins with Special Agent Elle Greenaway on what should have been a routine business trip to Dallas for a custodial interview with a convicted child murderer. Her journey is interrupted when a passenger, Dr. Theodore "Teddy" Bryar—a former renowned physicist—suffers a severe psychotic break.