Saw is a 2004 American horror film directed by James Wan, in his feature directorial debut, and written by Leigh Whannell from a story by Wan and Whannell. It is the first installment in the Saw film series, and stars Whannell, Cary Elwes, Danny Glover, Monica Potter, Michael Emerson, Ken Leung, and Tobin Bell.

The film tells a nonlinear narrative, revolving around the mystery of the Jigsaw Killer, who tests his victims' will to live by putting them through deadly "games" where they must inflict great physical pain upon themselves to survive. The frame story follows Jigsaw's latest victims (Whannell and Elwes), who awaken in a large, dilapidated bathroom, with one being ordered to kill the other to save his own family.

Plot:-

A photographer named Adam awakens in a dilapidated bathtub, with his ankle chained to a pipe. Across the room is oncologist Dr. Lawrence Gordon, also chained, and between them is the corpse of an apparent suicide victim holding a revolver and a microcassette recorder. Both men find a tape in their pockets, and Adam retrieves the recorder. Adam's tape urges him to survive, while Gordon's tells him to kill Adam by six o'clock or his wife Alison and daughter Diana will be killed. Adam finds a bag containing two hacksaws inside the toilet. Both men try to saw through their chains, but Adam's saw breaks. Gordon realizes that the saws are intended for their feet, and identifies their captor as the Jigsaw Killer, a serial killer testing his victims' will to survive through lethal traps referred to as "games", whom Gordon knows of because he was once a suspect.

Five months prior, Gordon, while discussing the terminal brain cancer of patient John Kramer, was interrogated by Detectives David Tapp and Steven Sing, who found his penlight at the scene of one of Jigsaw's games. Gordon's alibi cleared him, but he agreed to view the testimony of heroin addict Amanda Young, the only known survivor of one of Jigsaw's traps, who had been forced to kill and disembowel a man to obtain a key to free herself. After Gordon's release, Tapp and Sing find Jigsaw's warehouse using the videotape from Amanda's game. There, they apprehend Jigsaw and save a man from a trap, but Jigsaw injures Tapp and escapes. Sing pursues Jigsaw down a hallway where he accidentally triggers a shotgun trap and is killed.

In the present, Alison and Diana are held captive at their apartment as their captor watches Adam and Gordon through a hidden camera. The house is simultaneously watched by Tapp who, after being discharged from the police following Sing's death, has become obsessed with the Jigsaw case, and remains convinced that Gordon is the killer. Meanwhile, Gordon finds a box containing two cigarettes, a lighter, and a one-way cellphone. He recounts his abduction in a parking garage by a pig-masked figure. Adam recalls his own abduction when he returned home to find a puppet in his darkroom, where he stored photos of Gordon.