or "The Lethal Injection" or "The Acid Room" or "The Mother/Son Trap" or "The Mother & Son Trap"
In the last room, William Easton finds two cages on either side of him, one of which contains his sister, Pamela Jenkins—a well-known reporter of the Jigsaw cases. In the other stands Tara and Brent, the wife and son of a man who died after having his coverage rejected by William. Technically, the outcome of this test is determined by Tara and Brent's actions, not William's. Each cage contains a large tank of hydrofluoric acid. In the cage belonging to Tara and Brent is a switch labelled "Live" and "Die", giving them the final choice over whether or not William will survive. Before William arrived, the three initially thought the tanks of hydrofluoric acid were intended to kill them should they fail their test, but when Brent flipped the switch before William arrived, discovered it wouldn't work until he appeared for Tara's test, regardless of it's position.
|“||Hello Tara. My apologies for exposing you and your son to this kind of treatment, but I can assure you that it is not without reason. The man before you just made the sacrifices to save the life of a loved one. However, when given the opportunity to save your husband's life, he chose not to. Now you will be given the power to save a life. Will you grant this man the opportunity to continue living? Or will you dispense the same death sentence he issued your husband? Live or Die. The choice is yours."||”|
— Jigsaw Explains the rules to Tara
Tara attempts to pull the lever and kill William, but cannot bring herself to do it. However Brent, full of bitterness and hatred towards William for letting his father die, pulls the switch.
This causes a series of needles to swing down from the ceiling and pierce into William's back, injecting him with both tanks of hydrofluoric acid. The highly corrosive acid flows through his body, melting him from the inside out, and killing him as Pamela, Tara, and Brent watch in horror.
|“|| Hello Pamela. You've sensationalized my life, twisting the truth and exploiting my message for your own benefit--well today you will experience the meaning of sacrifice and you will see the consequence for those who unjustly hurt others."
— Jigsaw explains why she is involved in the game
This trap was nominated on Scream 2010 for Most Memorable Mutilation. (Body dissolved by hydrofluoric acid/the needle trap)