The murder games start up again and everyone thinks dead Jigsaw/John Kramer is behind it. Due to some clever jumping around in time it is revealed that the true killer is a copycat of Jigsaw attempting to recreate the first death games that were never discovered by the police.
I love how the current game takes place on the farm of John Kramer’s wife where the first game was played 10 years prior with the devices and body remains never discovered. Talk about inept detectives never going to search all locations associated with a serial killer. Luckily, the forensic investigator put together that a swine virus found on one of the current victims had also been found on the wife’s farm.
They try to be clever with twists and misdirection, but it ends up opening up gaping plotholes.