Adam Stanheight, a photographer, awakens in a full bathtub in a large dilapidated bathroom. He gets out and finds himself chained at the ankle to a pipe. Lawrence Gordon, an oncologist, is chained to a pipe across the room and between them lies a corpse, holding a revolver and a microcassette recorder. Adam manages to retrieve the recorder and they learn from tapes in their pockets what they must do: Adam must escape the bathroom before six o' clock, and Lawrence must kill Adam before six o'clock, or his wife and daughter will die and he will be left to die as well. Using a clue from the tape, Adam finds a bag in the toilet tank containing two hacksaws, though neither is able to cut through their chains. Adam's saw breaks and he throws it at a mirror in frustration. Lawrence realizes the saws are meant to be used on their feet and identifies their captor as the Jigsaw Killer, whom Lawrence knows of because he was once a suspect.