Saw V is a 2008 horror film directed by David Hackl (in his feature directorial debut) from a screenplay by Patrick Melton and Marcus Dunstan. It is the fifth installment in the Saw film series. The film stars Tobin Bell, Costas Mandylor, Scott Patterson, Betsy Russell, Mark Rolston, Julie Benz, Carlo Rota, and Meagan Good. The plot follows FBI Agent Peter Strahm as he pursues Detective Mark Hoffman after discovering his identity as one of the Jigsaw Killer's apprentices. Meanwhile, with John Kramer's threat that he will not go untested looming over him, Hoffman seeks to continue John's work and frame Strahm to keep his identity secret. The film also explores Hoffman's backstory and explains how he became Jigsaw's apprentice, while continuing several story lines started in Saw IV.
David Hackl served as the production designer of Saw II, Saw III, and Saw IV and second-unit director for Saw III and Saw IV before making his directorial debut with Saw V. Patrick Melton and Marcus Dunstan, the writers of the previous film, returned to write the film. Charlie Clouser, who provided the score for all previous Saw films, also returned to compose the score for the film. Saw creators James Wan and Leigh Whannell served as executive producers.
Saw V was released by Lionsgate in the United States on October 24, 2008, and received generally negative reviews from critics. Despite this, the film was a box office success, grossing $113.9 million worldwide. A sequel, Saw VI, was released in 2009.
Convicted murderer Seth Baxter wakes up chained to a table beneath a pendulum blade. A videotape informs him that he can release himself by crushing his hands between two presses. He does so, but the blade still swings down and bisects him as someone watches through a hole in the wall.
In the present, following the events of Saw IV, FBI Agent Peter Strahm escapes from the room he was locked in by Detective Mark Hoffman. He is then attacked by a figure in a pig mask and wakes up with his head sealed in a box being quickly filled with water. Outside, Hoffman delivers Corbett, the kidnapped daughter of Jeff Denlon, to the police and claims they are the only survivors. Strahm, having survived the trap by performing a tracheotomy with his pen, is brought out alive as well, much to Hoffman's shock.
During a press conference, Hoffman is promoted to Detective Lieutenant and credited with closing the Jigsaw case. Hoffman later finds a note in his office reading "I Know Who You Are," and learns of Agent Lindsey Perez's death while taking Strahm's cell phone from the police evidence room. At the hospital, Strahm tells Hoffman that Perez's last words were "Detective Hoffman" and questions how he escaped the plant. After being put on medical leave by his boss, Dan Erickson, Strahm, suspicious of Hoffman, decides to uncover his involvement with Jigsaw and takes case files of past Jigsaw victims to research them on his own.
In an underground sewer level, five people – fire inspector Ashley, real-estate company president Brit, journalist Charles, city planner Luba, and drug addict Mallick – awaken with collars locked around their necks, connected by cables to a set of blades mounted on the wall behind them. The keys to the collars are in individual glass boxes across the room. A videotape informs them that they are all connected and that they must "do the opposite" of their instincts if they are all to survive the tests ahead of them. Everyone survives the first game but Ashley, who fails to retrieve a key and gets decapitated when the collars retract. In the second room, which is filled with explosives on a timer, Mallick, Brit, and Luba each retrieve keys to bomb shelters set in the walls, leaving Charles to die when the timer expires and the explosives detonate. In the third room, Brit kills Luba and she and Mallick connect her corpse to five cables to complete an electric circuit that unlocks the next door. In the final room, Mallick and Brit find a machine fitted with five saws and a beaker requiring ten pints of blood to open the final door. They realize that all prior tests could have been completed without casualties if they worked together, and figure out their connection: they were all involved in a building fire that killed eight people. Mallick and Brit concede a truce and each slice an arm in the saws to provide the blood needed to open the final door.
Meanwhile, Strahm learns that Hoffman killed Baxter years prior as revenge for murdering his sister, and made it look like a Jigsaw game to get away with the crime. A series of flashbacks reveal how John Kramer abducted Hoffman after the fact, and blackmailed into becoming his first apprentice and helping him set up his future "games". Strahm concludes that everyone was meant to die at the plant except for Corbett and Hoffman, who would appear as a hero. Elsewhere, Strahm's activities draw Erickson's concern, which is further fueled when John's ex-wife Jill Tuck, who received a box and a videotape from John's will, approaches him and claims Strahm is stalking her. After Hoffman tells Erickson about Strahm's theory of a second Jigsaw accomplice, Erickson tries to call him. Hoffman intercepts the call on Strahm's phone and immediately hangs up. Now suspecting that Strahm is involved, Erickson has one of his agents track the phone's signal.
Following the signal to an observation room for the sewer game, Erickson finds the phone and his own personnel file, both planted by Hoffman. He also finds the still-living Brit and Mallick and calls for medical attention, before putting an all-points bulletin on Strahm, convinced that he is Jigsaw's successor. Meanwhile, Strahm follows Hoffman to the renovated nerve gas house and finds an underground room containing a box filled with broken glass shards and a tape. In the tape, Hoffman urges Strahm to enter the box, but he stops it short and ambushes Hoffman, whom he seals in the box. Strahm believes he has finally caught Hoffman, but the door to the room suddenly shuts itself and the walls begin to close in as the box is lowered beneath the floor. Strahm finishes playing the tape, which warns him that if he does not enter the box, he will die and be framed as Jigsaw's apprentice. Safe inside the box, Hoffman watches as Strahm unsuccessfully tries to escape the room and is ultimately crushed to death.