If a tree makes a yearly habit of telling a really convoluted, gory, incomprehensible story in the woods and no one thinks it's any good, does it get to tell the sequel next year?

It does if that tree is not really a tree but rather a series of movies named after the tree's archrival: the Saw franchise. I've long wondered how horror series like Friday the 13th and Nightmare on Elm Street kept going long, long, oh so very long after they'd produced anything worth watching. Seven Saws deep, I still have no goddamn clue.

-- Local show times, theaters, trailer.

For reference, there are now as many Saws as Star Wars movies, including that animated one that wasn't a fraction as good as the show on Cartoon Network. If The Hobbit ever makes it out of development alive, there will be as many Saws as Lord of the Rings plus Godfathers combined. Chew on that next time you're wondering whether the basic nature of humanity is good. Chances are we as a species are pretty close to Saw 3D: The Final Chapter: generally crummy, but sometimes we come through in the end.

With serial killer Costas Mandylor hunting her down, Jigsaw widow Betsy Russell goes to detective Chad Donella for protection. Meanwhile, Jigsaw survivor Sean Patrick Flanery hits the talk show circuit, exploiting his experience for fame and cash.

This does not escape Mandylor's attention. As he continues to pursue Russell by killing some dudes, he also kidnaps Flanery and puts him through a series of gruesome tests. Each failure will cost the life of one of Flanery's publicity crew--and, eventually, his wife--unless Donella can crack the case first.

Now in its seventh entry, the Saw franchise has come to be known for a few key signifiers. The grimy sets and mechanical traps that look like if The Legend of Zelda had an Industrial Temple. The blood and guts and self-inflicted torture. The shameless flashbacks and video clips that keep original Jigsaw Tobin Bell onscreen even though he's been dead for several movies now. And perhaps most distinctive of all, an utter and crippling incompetence.

Saw 3D hits all these notes but the total incompetence part. This is kind of amazing, because it's got the same writers as the last three Saws (Patrick Melton and Marcus Dunstan), and those films are so much garbage that if you watch them your TV will explode in a hail of eggshells, used coffee grounds, and soggy cabbage.

For a while, Saw 3D threatens to go the same route. It takes some time for director Kevin Greutert to bring its threads together as the story expands its vast mythology into bold new realms of Nobody Gives a Damn. Some people are killed in mildly creative and excessively gross ways, but since they're introduced moments before being sprayed across a junkyard, there's no real clue where this is going. Other than poorly. And with no idea how to use the whole 3D thing.

Saw gets its act together in the second half. Plots tie together. Things make sense. Your brain quits going "Who shot who in the what now?" and is freed up to start going "Oh, nasty." It becomes watchable, except for the parts where you have to cover your eyes.

Not great. Not an experience so revelatory your jaw will drop so bone-shatteringly hard that you yourself will look like a Saw victim. But watchable. By the lax standards of the last few movies, that's a big step up.

Then, it goes wild card.

Saw is supposed to be the end of the series. To their credit, Melton and Dunstan don't hold back, joyfully destroying the mythology they've taken so long to construct. There remains, as always, the question of who cares, but fans who've followed along to this point will get answers, closure, and a fat new twist. As a single film, Saw kind of sucks. Compared to other horror franchises, however, it's a pretty fine capper.

Grade: C