
This time around, the plot circles back to Detective Rigg (Lyriq Bent), who has been "so busy trying to stop [his] friends from making the wrong choices, that [he] has been unable to make any of [his] own." Just because the film opens with the gruesome and cinematic autopsy of serial-killing Jigsaw (Bousman's become a better director) doesn't mean that he can get away without being tested, and it isn't long before he finds himself with ninety minutes to save two of his friends: Detectives Hoffman (Costas Mandylor) and Mathews (Donnie Wahlberg, who Saw aficionados will better remember as the survivor of the last two films). Rigg's emotional, and in too deep, and he does more than play the game: he has to judge the other players, too. The costs have never been higher, or more emotionally manipulative: whereas Saw III asked Jeff (Angus Macfadyen) to salvage his own life by forgiving those who had initially ruined it (saving them from certain death), Saw IV seems to be recruiting Rigg as the next Jigsaw, with goading, blood-written notes asking Rigg to "See what I see," "Feel what I feel," "Save as I save," and "Judge as I judge." Other films have asked us to put ourselves in the shoes of a killer before, and have begged us to sympathize with murders, even -- in the most absurd of franchises -- to cheer for them. But few horror films have bothered to question what actually makes not just them, but those around them, tick.

Where the film lags is with the additional layer of Agents Strahm and Perez (Scott Patterson and Athena Karkanis), two FBI agents who are investigating Rigg, who has now gone missing. As access to Jill's revelations of John's past, they're invaluable, but as targets and unwitting players in Jigsaw's game, they seem meaningless, in reserve, perhaps, for Saw V. (To avoid spoiling anything, let's just say you don't see either one die.) Likewise with the scenes involving Hoffman and Mathews: while it's good to see characters come full circle, it's unsatisfying to see former players turned into helpless victims (although, in fairness to the twisted logic here, Mathews has yet to actually save himself). The only dramatic impetus in the film comes from Rigg's moral journey and Jigsaw's broken past, and everything else comes off as woodenly written filler -- sawdust, if you will.
At 110 minutes, it's the longest and most involved of the films, but it manages to fly through the familiar paces like a springloaded dart, and it caroms from deathtrap to deathtrap on surprisingly fresh feet. The Saw franchise has the dubious honor of spawning soulless torture flicks, horror with perhaps many points, but no actual point. But individually, it has grown more distinct, graphic, and well-made with each iteration, and Saw IV is an awfully good entry into the canon.