There is one reason, and only one, for anyone to check out "Vertical Limit." The hanging-by-a-fingernail mountain-climbing sequences are spectacular. The cliffhanger is such a primal movie experience that it can turn the most sophisticated moviegoer into a writhing 12-year-old, and director Martin Campbell, stunt coordinator Simon Crane and the special-effects crew serve up several lulus. Perhaps the best comes first: a stunning prologue on the sheer face of a Utah mountain, where brother and sister Peter and Annie Garrett (Chris O'Donnell and Robin Tunney) and their father (Stuart Wilson) find themselves dangling over the void suspended by a single fraying rope, facing a sacri-ficial Sophie's-like choice that, of course, will haunt the survivors for the rest of the movie. Bye, Dad.

You could leave after this opening sequence and almost feel you'd gotten your money's worth. That way you'd be spared the many risible moments that occur, with dismaying regularity, whenever there isn't an avalanche, nitroglycerin explosion, terrifying fall or other climbing catastrophe to interrupt the otherwise ludicrous story and the crummy dialogue.

Knee deep in cliches, writers Robert King and Terry Hayes send Annie up K2, the world's second highest mountain, with an arrogant billionaire (Bill Paxton) and a reluctant guide (Nicholas Lea). Of course they are trapped by an avalanche in a cavern, and given only 36 hours to live unless brother Peter and his motley team of rescuers can reach them in time. This unlikely crew includes Scott Glenn as a wizened loner with a dark agenda, a woman who would appear more at home on a fashion runway (Izabella Scorupco) and two Aussie stoners (Ben Mendelsohn and Steve Le Marquand), who look as if they could barely ascend a stairway.

"Vertical Limit" produces a decidedly split reaction in an audience. You gasp at the action sequences, then giggle at the drama, then gasp, then giggle until finally the filmmakers pile on one cliffhanger too many. By that point, the gasps have become muted by sheer disbelief.

Early on, at the base camp in Pakistan, where the international climbing crowd assembles and the air is filled with pot, hormones, beer and bravado, you get a brief taste of the movie that might have been. This is a scene we'd like to see the filmmakers explore, but any connection to the real world is quickly jettisoned for the hoariest tropes in the action-movie lexicon. Alternately generating adrenaline and ennui, "Vertical Limit" battles itself to a hard-earned draw.