Ten years after the death of John Kramer, criminal Edgar Munsen is shot and apprehended by Detectives Hunt and Halloran after activating a remote trigger. Meanwhile, five people – Mitch, Anna, Ryan, Carly, and an unconscious man, are held captive in a barn with chains around their necks. A tape recording from Kramer explains they must give a sacrifice of blood, and confess their sins. The chains pull them towards a wall of buzzsaws. Most of the group survive by cutting themselves to offer blood, but the unconscious man awakens too late to escape.
Their next test reveals that Carly is a purse snatcher, who accidentally caused the death of an asthmatic woman. To save the others from being hanged, she must inject herself with one of three needles – one containing an antidote to a poison in her system, one containing saline, and one containing acid. Ryan stabs Carly with all three to save himself, killing her.