Lieutenant Rigg, after becoming obsessed with finding his friend and former coworker, Eric Matthews (who had been missing for six months since the events of Saw II), was thrust into a game of his own with 90 minutes to locate Detective Matthews and Detective Hoffman. According to Jigsaw: after the abduction of Detective Matthews, Rigg had been too busy making sure his friends didn't make the wrong choices, in the process preventing himself from making the right ones. Rigg's obsession to save everyone was a fault in Jigsaw's eyes, and as such, he decided to test Rigg, to teach him how to "truly save a life." Rigg's tests were meant to urge Rigg to see the concept of salvation from Jigsaw's perspective, and ultimately show him why Jigsaw believes that it is wrong to save all of the people, all of the time. Rigg's trials began in his home, where he was attacked and rendered unconscious by a hooded assailant. Rigg eventually woke up in his bathroom, with a "?" painted on the door. Arming himself with a door-hook, he opened the door, pulling a trigger-pin that activated a television in the next room that explained his test, revealing to him that Eric Matthews was still alive.
|“||Hello, Officer Rigg, welcome to your rebirth. For years, you have stood by and witnessed as your colleagues have fallen. You have remained untouched, while Eric Matthews has disappeared. But, with your survival became your obsession. Obsession to stop those around you from making the wrong choices, thus preventing you from making the right ones. You wanted to save everyone. Tonight, I will give you the opportunity to face your obsession. Look closely. Eric Matthews is still alive. The block of ice he stands upon is melting. He has but 90 minutes to save himself. Detective Hoffman's fate is linked to Eric's survival. Heed my warning Officer Rigg: Their lives hang in the balance of your obsession. Will you learn how to let go... and truly save them? The choice is yours.||”|
— Jigsaw explaining the rules[src]