Saw V (2008)

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.