Having inherited the mantle of the serial killer known as Jigsaw (Tobin Bell) Detective Mark Hoffman (Costas Mandylor) tries to cover his tracks while executing yet another elaborate torture scheme and staying one step ahead of FBI agent Peter Strahm (Scott Patterson) who survived his previous encounter with Jigsaw but may not be so lucky this time around. Like so many horror franchises of recent (and not-so-recent) vintage — Halloween Friday the 13th A Nightmare on Elm Street — the latest Saw doesn’t deviate from the formula. Endlessly repeating the same rudimentary elements may spell big bucks at the box-office forked over by the Saw faithful but even die-hard fans will be hard-pressed to find something even remotely new or inventive here. In what must be an effort to mix things up screenwriters Patrick Melton and Marcus Dunstan revise (i.e. screw around with) some of the earlier film’s plot twists with “new” flashbacks that offer different perspectives than was first depicted. If this is intended to provide surprise to the well-worn storyline it isn’t successful. It only makes a murky story even murkier. Jigsaw may have met his end at the conclusion of Saw IV but Tobin Bell is all over the place this time around seen either in flashback or on television screens. With his menacing whispery delivery Bell can hardly be accused of sleepwalking through his role but one suspects that the basic enticements for him here were top billing — and the paycheck that goes along with it. The beefy Mandylor skulks his way through the one-dimensional role of Hoffman while Patterson brings a bit of intensity to his role as the dogged Strahm. Betsy Russell fondly remembered as a teen B-movie queen of the 1980s (Private School Avenging Angel) plays Jigsaw’s ex-wife while Meagan Good and Julie Benz (in an ill-fitting black wig) portray two of the latest “players” in the latest Jigsaw puzzle. Shawnee Smith Angus MacFadyen and Danny Glover who all met their onscreen ends in previous installments make token flashback appearances here — to no discernible effect. Mark Hackl the production designer of Saw II – IV who was originally tapped to direct the fourth installment now makes his directorial debut. As one might expect he retains the decayed urban design of the previous films (which he of course designed) and there are the requisite gallons of gore and guts for those who enjoy that sort of thing. What would the Saw films be without such visceral pleasantries? But for all the technical ingenuity of some of the lethal booby traps there’s a distinct dullness to the proceedings. Saw V is appropriately gruesome but it’s not particularly exciting or suspenseful. As a Halloween scare-fest it’s all trick and no treat … and yes the door is left wide open for another installment. Enough’s enough already.