In this promising but stunted delivery from M. Night Shyamalan and the writer of Hard Candy, the prince of darkness comes to "Philadelphia" (Toronto again but who's checking?), where five people get trapped in an elevator and start turning on each other nearly immediately. In case you missed the point of what's unfolding, one of the security guards watching it all unfold on the video monitors provides an extended narrated monologue about the morality tales his mother used to tell him about how the devil would roam the earth, looking for people to torment and show the error of your ways. Like most horror films, it's a morality play of a sort, with a glass skyscraper substituting for the Via Dolorosa.

The extended opening shots over the city's skyline promise that the natural order of things has been upended, presented as it is upside-down. Gleaming business district spires stab downward while Fernando Veláquez's score (a hyped-up, half-effective attempt to do Bernard Herrmann by way of Hans Zimmer) howls. Because, according to the narrator, it always begins with a suicide, we're given the sight of a man plummeting out of the top of a tower and crashing into a truck on a quiet street. The detective sent to investigate, Bowden (Chris Messina) - who first appears having breakfast with his AA sponsor, referencing forgiveness and the death of his family some years before so heavily that the lines may as well be covered in yellow highlighter - starts nosing around in the building itself.

Inside, five people of mostly equally ugly dispositions have been trapped in an elevator. Though this would provide most writers with an opportunity for some snappy exchanges and thumbnail character studies, Brian Nelson misses the chance almost completely. Instead, the workings of the supernatural come almost immediately into play as the five - a security guard, a smarmy salesman, a quiet tough guy and two women differentiated mostly by one being old and the other young - start panicking after the lights go out and one of the women finds herself with an unexplained bloody wound on her back. As the hapless security guards and maintenance man try to fix the problem (it seems a woefully understaffed building), things deteriorate inside the elevator. Then the lights flicker off again, a shattering of glass is heard, and when they come back on, somebody is dead.

If Nelson, writing from an idea by Shyamalan, could have come up with any memorable dialogue for these sequences, they might have formed a sophisticated and dark little fable along the lines of his Hard Candy. But as it is, almost all the character development is supplied by Bowden, who digs up each of the five's background and serves as the story's chief expositor - that is, when he's not trying to stop the security guard from clutching his crucifix and praying. "I don't believe in the devil," Bowden growls in the voice of the fallen disbeliever just itching to be converted back to the faith, "We don't need him." It's a credit to Messina that he can bring enough nerve and conviction to the role to make lines like this seem even partially credible.

Like so many of Shyamlan's stories, this one hinges almost entirely on themes of faith and sin (witness Signs, in particular). In the end, it's not giving too much to say that the lessons learned (highly bloody or not) will not be that dissimilar from those disseminated in Sunday schools across the land. As to whether the multiplex is the right place for such educational fables to be played out? Well, the devil works in mysterious ways.