The central twist of Reservoir Dogs is the reveal that Mr. Orange (Tim Roth) is the undercover police informant. The entire film is structured around the mystery of the "rat," and this revelation re-contextualizes every interaction. Mr. White's fatherly protection of Orange becomes tragic irony, as he is unknowingly defending the very person responsible for their predicament. The extensive flashback sequence dedicated to Mr. Orange shows his recruitment, his training, and how he masterfully created a convincing criminal persona by memorizing a detailed anecdote—the "commode story."
The film's climax is a bloody Mexican standoff. When crime boss Joe Cabot arrives, he immediately identifies Orange as the rat and prepares to execute him. Mr. White, in a fatal act of loyalty, defends Orange, drawing his gun on Joe. Joe's son, Nice Guy Eddie, then draws on White. All three fire, killing Joe and Eddie and mortally wounding White. As White lies dying, cradling Orange, Orange confesses his true identity. Heartbroken and betrayed, White presses his gun to Orange's head. The police storm the warehouse and demand White drop his weapon. He shoots Orange and is simultaneously gunned down by the police. The only potential survivor is Mr. Pink, who fled with the diamonds just before the standoff, but sounds of a struggle and police activity outside suggest he does not get away.