At this point, it's clear that writer/director M. Night Shyamalan has lost something off his fastball. The question is, can he still fool viewers with his off-speed stuff?

In "The Happening," Shyamalan is only partially successful. The film is thought-provoking and spooky, and gets off to a strong start. It gets more contrived and preposterous as it goes on, however, and the payoff is a bit disappointing.

Mark Wahlberg stars as Elliot, a Philadelphia science teacher with a strained marriage and a big problem: All across the Northeast people are being infected by a mysterious toxin that gives them an irresistible urge to commit suicide in violent and graphic ways. This is where the movie's marketing campaign -- the first I can ever remember that is almost completely based on the movie's rating ("See the director's first R-rated feature!!") -- comes into play, and the blood and gore and decapitations do add to the sense of dread and terror.

Elliot and his wife, Alma (Zooey Deschanel), best friend Julian (John Lequizamo) and Julian's young daughter Jess get out of Philadelphia in time, but that only postpones the inevitable, and soon they're fleeing across the Pennsylvania countryside with no particular goal in mind.

"The Happening" does a good job of portraying the panic of people faced with an unknown danger. Is this a terrorist attack? Alien spores? Rage virus?

Wahlberg and Deschanel are serviceable as the leads, but Shyamalan does them no favors, with creaky and awkward dialogue and some clunky plot devices designed to give Elliot a chance to piece together what's really happening.

"The Happening" is better than the flop "The Lady in the Water" and on par with the mildly disappointing "The Village." It still isn't close to the director's best.

It's been a half-dozen years since Shyamalan's good stuff --"Signs," preceded by "Unbreakable" and "the Sixth Sense." I think he's got another one or two of those in him, but he's trying his fans' patience.

Rental Recommendation: 1962's "Day of the Triffids" is hopelessly outdated but still kind of cheesy sci-fi fun. What would happen if most of humanity was blinded, then set upon by man-eating plants? Grade: C.