Jen Tracy Duplass, Sony Classics Pictures
The twists and turns in "Baghead" will keep viewers on their toes.
BAGHEAD — *** — Steve Zissis, Ross Partridge, Greta Gerwig; rated R (profanity, violence, vulgarity, brief nudity, brief sex, slurs, brief drugs)

"Baghead" appears to turn into a completely different movie about halfway through.

It's a conundrum wrapped up in feature-film form. Is the ultra-low-budget production an inside-filmmaking expose? A slasher-horror movie? A romantic comedy-drama? Or perhaps a bizarre combination of all three?

That's part of the film's fun, though. Just when you think the film is about to zig, it zags and heads another direction. And it's smart enough to cut things short before it wears out its welcome and before it gets too predictable.

The movie follows a few failed actors who are attempting to become filmmakers. Best friends Matt and Chad (Ross Partridge and Steve Zissis) are headed to a cabin in the woods, where they're hoping to write a screenplay and perhaps film a movie over the weekend.

Accompanying them are two women — Brad's on-again, off-again actress girlfriend, Catherine (Elise Muller), and Michelle (Greta Gerwig), who's being pursued romantically by the neurotic, pudgy Chad.

Inspiration of sorts strikes when Michelle has a drunken nightmare about being stalked by a man with a mask. So that becomes the focus of their project.

Unfortunately that's cut short when Michelle spies someone — a menacing someone — who's wearing a mask. She's worried about whether this is real, or whether one or more of the others is playing an elaborate prank.

Screenwriting-directing team the Duplass brothers (2005's "The Puffy Chair") were wise to cast these fresh faces. All of them look like normal people, which is one of the reasons why we care about what happens to them in the end.

And at one point, the Duplasses seem to be taking a few jabs at "The Blair Witch Project" by spoofing the hand-held "shaky-cam" bit. But they don't overdo it, and their other filmmaker and show-biz volleys often hit their targets.

"Baghead" is rated R for strong sexual language (profanity and suggestive talk and references), some brief strong violence (a stabbing, as well as vehicular mayhem and violence), brief flatulence humor (belching), brief female and full male nudity, some sexual contact, a couple of derogatory slurs, and brief drug references (cocaine). Running time: 84 minutes.

E-mail: [email protected]