Horror films sometimes offer a good showcase for older actresses. Gena Rowlands, who used to star in films by the late John Cassavetes, has her best role in quite a while in The Skeleton Key.

In a summer of otherwise disappointing rehashes and remakes, The Skeleton Key stands out as a fairly clever horror effort that relies on characters and original story elements rather than high-speed chases and effects. It's not a perfect movie, but stays on track enough to satisfy fans of gothic horror.

Rowlands plays Violet Devereaux, one of the owners of a crumbling mansion that seems to rise out of the Louisiana swamp, surrounded by Spanish moss-covered trees. Her husband, Ben Devereaux (played by John Hurt), recently had a stroke. Violet advertises for some help, and gets it in the form of a live-in attendant named Caroline (Kate Hudson). A young lawyer called Luke, played by a sleepy-eyed and humorless Peter Sarsgaard, convinces Violet to give Caroline a chance — mostly because all the other applicants have run off in terror.

Caroline is from New Jersey and doesn't know much about the ways of the South. Her naivete helps the audience through the plot, as almost everything has to be explained to her. Right away, the gloomy house starts to act up with requisite creaking sounds. There are big stains on the walls where the mirrors used to be. Violet explains that old people don't like to look at what has become of themselves, but there is obviously more to it.

The title comes into play when Violet, oddly, gives Caroline a skeleton key that opens all the locks in the house. It makes no sense that Violet would want Caroline poking around in the secrets of the old house — or maybe it does. Ben had his stroke poking around up in the attic, and there is one door there that can't be opened. Caroline can't help but poke around in things best left untouched. Her most interesting find is the Receipt Book of Papa Justify, a dusty, handmade tome filled with cryptic diagrams.

She describes some of her findings to a friend, who helpfully explains that it is related to hoodoo, a sort of mix-and-match magical practice not to be confused with voodoo. With hoodoo, for example, a line of brick dust by the door can protect you. Hoodoo in the film is handled with a minimum of computer tricks.

Director Iain Softley, whose previous big film was K-Pax, pulls out all the stops for a crucial flashback sequence involving Papa Justify. He tosses in black-and-white mixed with color footage, Matrix-like blasts of fast motion and a smeary screen. It's a touch excessive. But the rest of his direction sets an ominous mood quite well, and he gets some good mileage out of extreme close-ups through keyholes.

John Hurt has perhaps the most difficult role in the film as the stroke victim. He has to convey some important information without much movement and almost no words. Perhaps the corniest part of the movie is when he writes "Help me" on a sheet. It's clear he needs help — he could have used the same space to explain what is going on in a few short words.

Rowlands' role also has complications. She puts on a polite, oblivious face for Caroline. But the audience can tell that she knows more than she lets on about Ben and his unusual stroke.