DON'T see this unless you've got a serious head for heights.

The film opens promisingly, with brother and sister Peter (Chris O'Donnell) and Annie (Robin Tunney) Garrett out for a spot of climbing with their dad (Stuart Wilson) - but with tragic consequences.

Three years on, Peter still can't bring himself to face the mountains, and is

working as a wildlife photographer. But Annie is one of the world's top climbers, and the siblings bump into each other at base camp on K2, where she is about to embark on an ascent to coincide with the launch of a new airline by ruthless Texan tycoon Elliot Vaughn (Bill Paxton).

The assault on the summit soon runs into trouble, with storm clouds

gathering on the horizon in more ways than one. Vaughn and Annie are trapped in an icy grave at 26,000ft, along with expedition leader Tom McLaren (Nicholas Lea).

Peter comes out of mountaineering retirement to join the rescue mission in a frantic race against time. As does reclusive Montgomery Wick (Scott Glenn), who lost his toes to frostbite in an unsuccessful attempt to rescue his wife a few years before, and has spent the time since

scouring the peak for her frozen body. Not forgetting beautiful French-Candian medic Monique (Izabella Scorupco), who has taken something of a shine to Peter.

The rescuers are carrying high-explosives to blast their way in to the trapped trio's tomb. The slightest jolt and they'll be mincemeat. Meanwhile, in the depths of K2, Vaughn is prepared to sacrifice the other two to ensure his own survival.

So far, so good. But the credibility gap between a believable adventure and high-level hokum grows into a yawning chasm as avalanches and explosions rapidly pile on top of each other.

Vertical Limit follows the first rule of all those celebrity-studded disaster movies of the 1970s ... if something can go wrong, be assured that it will. So just when you think everything's going swimmingly, it quickly turns pear-shaped. The plot goes belly-up more times than an over-affectionate cat.

Still, the climax - when it finally arrives - neatly ties in with the impressive opening, topping and tailing proceedings quite

nicely; director Martin Campbell (Goldeneye, The Mask of Zorro) handles the action sequences with some style;

and O'Donnell and Glenn give solid,

understated performances.

But the film overall is over-cooked. It sets out to be taken seriously and ends up as almost laughable. With tighter editing and fewer cartoon characters it could

have been very good. And how can the supposedly feel-good ending really work when, if you think about it, so many have died to save so few?