It has nothing to do with the main character from the last movie trying to escape the clutches of Jigsaw’s post-mortem insanity, as was originally reported, but instead details the investigation that goes on when the bodies of Jigsaw and Amanda are discovered, and a SWAT officer who is thrust into Jigsaw’s sick game, even though the man himself is quite dead.
You can get the fully detailed plot breakdown, as well as a full cast list if that’s that sort of thing you’re into, over on Bloody Disgusting. Saw IV is in theaters October 26th, 2007!