Dir: Darren Lynn Bousman. US. 2007. 93mins.
Cinematic trends come and go, but the resilience of the Saw franchise continues unabated. Grimly efficient in a manner consistent with previous installments, Saw IV demonstrates that this well-oiled horror machine is showing noticeable wear and tear, but nevertheless enough of the moving parts still work efficiently to please the film's core gore crowd.

Opening in its annual late-October slot, Saw IV collected an estimated $32m in the US this weekend. That would put it on a comparable pace with 2005's Saw II ($87m domestic, $61m international) and last year's Saw III ($80m domestic, $85m international). With other recent horror films experiencing underwhelming box- office performances, the ongoing strength of the Saw series suggests that the granddaddy of the so-called 'torture porn' genre has greater longevity than the sub-genre it helped birth. Lionsgate can look forward to brisk future DVD sales as it prepares for the inescapable Saw V.

Even though serial killer John 'Jigsaw' Kramer (Bell) died at the end of Saw III , FBI agents Strahm (Patterson) and Perez (Karkanis) search for a mysterious accomplice who assisted Jigsaw with his murderous puzzle games. Their quest leads them to suspect his ex-wife Jill (Russell), who offers clues to his past which help flesh out the motivating factors that drove him to homicide in the first place. While the investigation proceeds, policeman Rigg (Bent) is kidnapped and forced to play one of Jigsaw's elaborate games, which is being executed by the accomplice.

Considering that the four Saw films have opened around successive Halloweens, one has to admire the workmanlike precision of the film-makers to crank out another installment each year. And while none of the entries would be confused with a masterpiece, director Darren Lynn Bousman (who has helmed each of the three sequels) deserves credit for supplying these films with enough dire menace and intrigue so that they don't become dull or hopelessly convoluted. Especially in comparison to the bloated, self-important sequels that followed in the wake of box- office behemoths like Pirates Of The Caribbean and The Matrix, at least the Saw films have been consistently watchable, no matter how gruesome the onscreen violence becomes.

Screen writers Patrick Melton and Marcus Dunstan, new to the series, follow in the footsteps of Saw III by dividing the action between extended flashbacks of Jigsaw's past and horrific present-day Jigsaw games that his victims must outwit if they wish to stay alive. Saw IV's surprises about Jigsaw's past aren't as engaging as the ones uncovered in the last film, but the writers throw enough red herrings and twists into the contemporary investigation to keep the final reveal of Jigsaw's secret accomplice a complete mystery. Unfortunately, that final reveal turns out to be more frustrating than enlightening or even logical.

Since suspension of disbelief is a must for these films to work - including not questioning how one man and a few loyal lieutenants can keep concocting so many ingenious booby traps and complicated citywide death games - it may seem naïve to complain how unbelievable Saw IV gets as its draws to its conclusion. Nevertheless, the Saw films live or die by the strength of their conclusions, since the films themselves are constructed as puzzles whose pieces never come together until the end. On this measure, Saw IV is the weakest of the series, tying together the many hints littered through the narrative but doing so in a way that feels slapped together. At this point, setting up enough plot strands for future Saw movies is a greater priority than delivering a fully satisfying self-contained entity.

Even though his character is now a corpse, Tobin Bell still sets the film's tone, supplying enough gravitas without falling into self-parody. As in previous installments, the performances around him veer from amateurish to histrionic to sturdily anonymous, so it's up to Bell to anchor the proceedings, especially as the films delve deeper into his past to explore his demons. Bell remains an intimidating but soulful villain, as close as this new era of horror films has come to a class act. Without question, future sequels will have to contort themselves further to figure how to keep a dead man at the narrative's center. Death may not have halted the Saw moneymaking machine, but it's certainly thrown a wrench into the works.

Production companies/backers
Lionsgate (US)
Twisted Pictures (US)

US distribution

International distribution

Executive producers
Daniel Jason Heffner
James Wan
Leigh Whannell
Stacey Testro
Peter Block
Jason Constantine

Gregg Hoffman
Oren Koules
Mark Burg

Greg Copeland

Screen play
Patrick Melton
Marcus Dunstan

David A Armstrong

Kevin Greutert
Brett Sullivan

Production design
David Hackl

Charlie Clouser

Main cast
Tobin Bell
Costas Mandylor
Scott Patterson
Betsy Russell
Lyriq Bent
Athena Karkanis