"The Guardian" has high aspirations. Directed by William Friedkin, best known for "The Exorcist" (he also won an Oscar for "The French Connection"), this is a big-budget horror film with a glossy, artsy look and a few compelling characterizations.

But when all is said and done, it's really just "Attack of the Killer Tree."

What we're dealing with here is the ancient druid rituals about trees as objects of worship and sacrifice. In the opening moments Jenny Seagrove, a trusted babysitter to a young couple, runs off with their baby and sacrifices it to a tree deep in a California forest. The baby's face becomes a carving on the trunk.

But the film is really about her next victims, young marrieds Dwier Brown and Carey Lowell, who have a baby and also hire live-in nanny Seagrove. We know, of course, that Seagrove has evil powers and is getting close to the child so she can spirit it away and sacrifice it to the tree. But Brown and Lowell naturally take a bit longer coming to that conclusion.

Most of the movie is made up of eerie settings and zigzag camera angles and offbeat colored lighting, much of it quite effective in building and sustaining suspense — Friedkin is a seasoned director who knows how to manipulate audience emotions.

But then a character opens his or her mouth and spoils everything.

Loaded with little plot holes and illogical development, "The Guardian" asks a lot of us in the first place as we attempt to accept this killer tree in the forest.

But as the film progresses — or regresses — the suspension of disbelief rapidly dissipates, which is deadly to the film's shock value. Friedkin tries to cover up the story's inherent weaknesses with camera tricks and the spilling of gore galore. But it doesn't help much.

Friedkin last year gave us the cop-thriller "Dead-Bang" with Don Johnson. Between that one and "The Guardian" he's on a real downhill roll.

"The Guardian" is rated R for a plenty of violence, nudity, sex and profanity.