In Saw III, Jigsaw (played by Tobin Bell) is dying and in need of a successor to continue his work of testing people's will to survive. He chooses Amanda (played by Shawnee Smith), a former drug addict and survivor of one of his previous tests. However, Amanda's methods become increasingly violent and unpredictable, leading Jigsaw to doubt her and seek out a new apprentice.
Meanwhile, Doctor Lynn Denlon (played by Bahar Soomekh) is kidnapped and taken to an abandoned warehouse, where Jigsaw forces her to keep him alive using her medical expertise while he puts Jeff Reinhart (played by Angus Macfadyen), a man who has become consumed by revenge for the death of his young son, through a series of tests designed to make him confront his anger and forgive those who wronged him.
As the two storylines converge, secrets are revealed and characters are forced to make impossible choices to survive. Saw III is known for its gruesome and elaborate traps, as well as its exploration of Jigsaw's twisted philosophy and motivations.