When a cop snaps, he threatens to take a building full of people with him.

Bernie Shepard comes home with a shotgun. He opens the door to his bedroom, and sees what he expected - his wife in bed with another cop. Two pumps of the shotgun take care of them, and Shepard carries out the rest of his plan. Accompanied by his nameless dog, this half-mad young detective goes to the roof of his apartment building, where he has built a small fortress stocked with food, water, and weapons. He loads his guns and awaits the police.

Talking Shepard down falls to Abe Lieberman and Bill Hanrahan, the odd-couple partners in Chicago homicide. As soon as they make contact, Shepard names his demands: He wants to talk to a TV crew and to the new police captain. The building is rigged with explosives, he says, and he is ready to pull the trigger. To stop this renegade cop, Lieberman and Hanrahan will have to kill him - or try to understand what made him snap.