THE BIG question hanging over "The Blair Witch Project" is simple but devastatingly effective.

What happened to the three friends, Heather Donahue, Joshua Leonard and Michael Williams, who dove deep into the Maryland woods in search of witches and never returned?

The date was Oct. 21, 1994, according to the opening titles. It's always creepier with a date, isn't it? You can almost hear Robert Stack's voice in the narration, as the titles also inform us: "One year later, their footage was found."

The trio in the movie -- led by Donahue (and portraying themselves) -- was trying to make a documentary about the Blair Witch, a spirit believed to be haunting this sparsely inhabited corner of Maryland's Black Hills Forest.

But all that remains of their five-day trek into the heart of darkness is the footage in Leonard's 16mm camera and Donahue's High-8 video. Which we get to watch.

Well, what happened?

You won't find out by reading this. But I will say "Blair" was a good college try of a flick -- as good an effort as one could expect of a film with no budget, one pretty good idea and a few creative minds trying to come up with an MTV-age campfire movie. Imagine a collaboration between George "Night of the Living Dead" Romero and the makers of "The Real World."

Donahue is the director of this witch-finding documentary, a young, idealistic person with a fairly good idea of the history behind the Blair Witch. Too bad she's not too hot with scouting skills.

Before embarking into the woods, Donahue and crew interview the locals, who have heard a story or two about that Witch Up There. That's another essential ingredient in a horror flick -- the creepy past that preceded all this. Good stuff!

With these veiled, anecdotal warnings, the film crew -- young, ambitious and dude-like -- heads straight for the heart of darkness.

Or Maryland, anyway. Although they have a map and compass, they become hopelessly lost. As they realize how unmoored they are, their initial good humor becomes fraught with anxiety, tears, disbelief, boredom, depression and occasional yelling.

Was that the same log bridge across the creek they saw hours earlier? Do they go south or east now? What are those noises outside their tents at night? What happened to the smokes? As they become increasingly frayed and freaked, we start preparing for the worst. And that's where I'm leaving it.

"The Blair Witch Project" is certainly assured and savvy enough for the government work that we romantically refer to as "American Independent Moviemaking." I was hooked on its creepy possibilities right through to the end. What's good about this film is the way its actual creators -- Ed Sanchez, Dan Myrick and Gregg Hale -- use ellipses and suggestion to make our minds do most of the work. Most of the time, it's what the three witch-searchers don't see -- but fear -- that gets our petrified juices flowing or curdling. This is low-tech inventiveness at its best. And that, surely, is what campfire storytelling is all about.

THE BLAIR WITCH PROJECT (R, 88 minutes) -- Contains macabre material and strong language. At the Cineplex Odeon Outer Circle.

CAPTION: Heather Donahue turns the camera on herself in "The Blair Witch Project."