A year-end blowout sale becomes literal for a used-car lot after one of its owners is killed when a bomb explodes. While the squad tries to find who is responsible, Rusty dons a bullet-proof vest under the watchful eye of Lt. Chuck Cooper, an SIS (Special Investigation Section) supervisor, in an attempt to catch the person responsible for threatening his and Sharon’s life.

The squad must work quickly to track down a serial killer before he strikes again. Meanwhile, things get dangerous over a game of chess.