Following the death of the Jigsaw Killer, his apprentice continues the gruesome legacy, setting up a new series of deadly traps. The story focuses on two main paths: one tracking the progress of SWAT Commander Rigg, who is obsessed with saving his friends from the killer's sadistic games, and the other following FBI agents Strahm and Perez as they delve into the killer's past to understand his motivations. Rigg is thrust into a personal trial by the killer, given 90 minutes to overcome several challenges if he hopes to save his friends, forcing him to face the moral dilemmas at the heart of the killer's philosophy.

As the investigation deepens, connections between the victims and the nature of the killer's games are uncovered, revealing a complex web of deceit, suffering, and redemption. The killer's intricate planning puts every character to the test, making them confront their darkest fears and moral failings. Meanwhile, the agents uncover unsettling evidence that suggests the killer's legacy is far from over, hinting at a deeper network of accomplices that extends the reach of his influence beyond the grave. This discovery sets a chilling precedent, positioning the killer's philosophy as a twisted form of justice that continues to challenge and horrify in equal measure.