When detective Eric Matthews is called to a crime scene of a victim of Jigsaw, he finds a lead to the place where he is hidden. Once there, he realizes that Jigsaw trapped his son Daniel Matthews with three women and four men in a shelter, and they are inhaling a lethal nerve gas. If they do not use an antidote within two hours, they will die. Eric follows with increasing desperation the death of each member of the group in monitors, while trying to convince Jigsaw to release his son.

Jeff is an anguished man, who grieves and misses his young son that was killed by a driver in a car accident. He has become obsessed for revenge against the man and reckless with his wife and daughter. When Dr. Lynn Denlon, who has troubles with her marriage, is abducted by the deranged Jigsaw's apprentice Amanda, she is brought to a gruesome warehouse to keep John Kramer alive in spite of having a terminal brain tumor. Amanda puts a necklace gadget full of explosives around Dr. Lynn's neck connected to John Kramer's life support system, and tells her that if he dies the device will explode. Meanwhile, Jeff is submitted to a sick game of forgiveness with surprising dark consequences.

Jigsaw and his apprentice Amanda are dead. Now, upon the news of Detective Kerry's murder, two seasoned FBI profilers, Agent Strahm and Agent Perez, arrive in the terrified community to assist the veteran Detective Hoffman in sifting through Jigsaw's latest grisly remains and piecing together the puzzle. However, when SWAT Commander Rigg is abducted and thrust into a game, the last officer untouched by Jigsaw has but ninety minutes to overcome a series of demented traps and save an old friend or face the deadly consequences.

Detective Mark Hoffman is deemed hero after he saves a young girl and "escapes" one of Jigsaw's games, or so it seems. Special Agent Peter Strahm is suspicious of him after his assistant Agent Lindsay Perez says Hoffman's name. While Agent Strahm looks into Detective Hoffman's past, a group of five people who helped burn a building which was supposedly abandoned, face a series of tests set up by the Jigsaw killer.

The body of Agent Strahm is completely smashed and destroyed and Detective Mark Hoffman frames him. Strahm is accused of being Jigsaw's apprentice and the FBI chases him. Dan Erickson calls Hoffman and he learns that Agent Lindsey Perez has not died. When Dan finds a tape with the voice of the killer, he invites Hoffman and Perez to go with him to the laboratory to see the progress with the identification of the real voice. John's widow Jill Tuck receives a box from his lawyer with six envelops with instructions and she gives the first five to Hoffman. The unethical CEO of the Umbrella Health, William Easton, and his team are abducted and William is forced to play a game and choose who will live or die to save his family and him.

Detective Matt Gibson chases the psychotic Detective Mark Hoffman while Jigsaw's widow Jill Tuck tries to kill him as assigned by her husband. However he escapes and Jill meets Gibson and offers to sign an affidavit listing the murders committed by Hoffman. In return, she requests protection. Meanwhile, the prominent Jigsaw survivor and leader of a support group Bobby Dagen is abducted with his wife and friends and forced to play a mortal game to save himself and his beloved wife.

Charles Rankin is a professor in a respectable Connecticut town about to marry the daughter of a U.S. Supreme Court justice. But his name is fake and his past is filthy. An earnest convert to Christianity, who once ran a Nazi concentration camp, is capable of exposing him. So "Rankin" kills this little old man and buries his body in the forest. But he isn't safe because an investigator from the War Crimes Commission is on his tail. Rankin will need his own wife to help him elude capture. But his fascination with the local clock tower may prove his undoing.

Whilst out on a rowboat with his wife Louise, John Haloran has a heart attack and dies. She casts his body overboard and hides his death telling the family he left on an urgent business trip. Louise's main concern is that she can only hope to inherit part of his family fortune if he's still alive. The Halorans are a strange family. They are still grieving over the death of the youngest daughter, Kathleen, who drowned in a pond when she was a young child. The family hold an annual ceremony of remembrance, on the anniversary of her death. But this year someone is wielding an ax...intent on murder.

Regina is about to divorce her husband when she finds that he has been murdered after converting every penny they owned to cash, which is also missing. She meets Cary Grant who changes his name every 15 minutes or so and is interested in her husband's money, which seems to have come from a WWII payroll he stole. His partners in crime are also very interested in where the money is, as he stole it from them as well. Everyone assumes Regina MUST know where the money is. The situation becomes more tense when the searchers begin turning up dead.