Dispensing with the niceties straight away, the latest instalment in horrordom's nastiest franchise begins where the last one ended.

Cop Donnie Wahlberg (in cameo) is chained up in that filthy bathroom with a painful dilemma involving a saw and/or a large stone slab. The game is, quite literally, a foot.

Returning director Bousman then severs ties to Saw II yet sticks to its template by despatching the only other survivor with a very painful acid test, plus another random victim for good measure. Ten minutes in and everyone’s faces will be set to 'wince'.

Expect them to stay that way with the unrelated appearance of troubled doctor Lynn, because not only is she captured and forced to wear an explosive collar, she is terribly acted by Bahar Soomekh.

The device around Lynn's neck is the handiwork of Amanda (Smith) who, you may remember, survived a game set by sadistic nutjob Jigsaw (Bell) only to be driven mad by Stockholm Syndrome. She is now his eager apprentice.

Jigsaw, aka John Kramer, has an inoperable brain tumour but he's not about to let that ruin his fun. Lynn's job is to keep him alive in his house of horrors until his latest, and possibly last, game is over. Otherwise, her head blows up.

That game involves Jeff (Angus Macfadyen, once of Braveheart), a desperate chap who wakes up in a crate to learn that he now has the chance to wreak revenge on those responsible for the death of his son.

With Amanda becoming increasingly unhinged, Lynn makes Jigsaw comfortable by drilling holes through his skull and Jeff staggers through the torture chambers that comprise Jigsaw’s lair. It makes the London Dungeons look like Santa's grotto.

Each room contains a person locked, bound or nailed to the sort of contraption that would make the Spanish inquisition shudder: a shower/freezer; an industrial mince-maker (with rotting pig carcasses); a mechanical wrack...

Though it delivers all the splat-happy nastiness you would expect, the methodology is getting samey – and gratuitously sick. Jigsaw's twisted moralising is no justification for what he does to people who aren't bad, just human.

Here's a game: try to work out how a mentally unstable woman can capture at least six people - unnoticed - from separate locations and set up this whole sick shebang within a few hours.

Also pay attention at the end because - bearing in mind all its talk about playing by the rules - you’ll find that Saw III cheats. This series has lost its edge - it's time to play something else.

Elliott Noble