August 12, 2005 | A genuinely clever final plot twist and a few modestly creepy scenes are not quite enough to seal the deal for The Skeleton Key, a low-voltage shocker set in the bayou country near New Orleans. Surprisingly short on spooky atmosphere, this bland gumbo of black magic and psychological suspense will scare only those moviegoers easily upset by the wanton killing of time.

Kate Hudson comes off as equal parts plucky heroine and distressed damsel as Caroline Ellis, a hospice nurse who relocates from The Big Easy to the backwoods of Terrebonne Parish. She’s hired by family retainer Luke Marshall (Peter Sarsgaard) to help elderly Violet Devereaux (Gena Rowlands) care for Ben (John Hurt), her stroke-incapacitated husband, in their spectacularly decrepit plantation home.

The longer she remains at Casa Devereaux, however, the more Caroline comes to question whether Ben really did suffer a stroke. Maybe, just maybe, his condition has more to do with a locally popular folk magic known as hoodoo. (Not voodoo, you understand, but something much more potent).

On the other hand: Maybe, just maybe, Caroline should be a lot more careful about who and what she chooses to believe.

Skeleton Key is the kind of by-the-numbers thriller in which supposedly smart people make incredibly dumb choices, and key supporting players are extremely unconvincing while disguising the not-so-hidden agendas of their characters. (Late in the film, when Caroline rushes to the home of an obviously untrustworthy person to seek assistance, you can be forgiven for shouting rude things at the screen.) Hudson throws herself into her role like a game trouper, and even allows director Iain Softley (K-PAX) to exploit her for some totally gratuitous peek-a-boo nudity. But even that doesn’t help much.

It all boils down to this: When it comes to truly frightening supernatural thrillers, some hoodoo, and some hoo-don’t. The Skeleton Key doesn’t.