Several years after a fatal climbing accident claimed their father's life, Peter Garrett (CHRIS O'DONNELL) and his sister, Annie (ROBIN TUNNEY), have gone their separate ways. He's now a wildlife photographer while she's a mountain guide, and they've never resolved their feelings about that fateful day.
They're reunited at the base camp of K2, the world's second highest peak where Annie and fellow mountain guide, Tom McLaren (NICHOLAS LEA), are to lead egomaniacal and ultra wealthy Texas businessman, Elliot Vaughn (BILL PAXTON), to the summit so that his photo can be taken just as the inaugural flight of his new airline flies overhead.
Despite an approaching weather system that could spell disaster for their effort and lives, Vaughn bullies his team into continuing. An accident and then fatal avalanche, however, puts an end to their expedition and kills everyone but Annie, Tom and Vaughn who now find themselves buried in an icy cave with both supplies and time running out.
Realizing that, Peter scrambles to assemble a rescue team that must ascend the summit after being dropped off part of the way up by Pakistani chopper pilot Major Rasul (TEMUERA MORRISON). Among those volunteering for the rescue effort is Skip Taylor (ROBERT TAYLOR), another expert mountain climber; Kareem Nazir (ALEXANDER SIDDIG), a friend of Peter's who lost a family member in the accident; Malcolm (BEN MENDELSOHN) and Cyril Bench (STEVE LE MARQUAND), two goofball, but seasoned Australian brothers; Monique Aubertine (IZABELLA SCORUPCO) an occasionally surly French-Canadian nurse; and finally Montgomery Wick (SCOTT GLENN), a grizzled mountain climbing veteran whose wife died while on an earlier expedition with Vaughn.
As Peter's team splits up into three twosomes and each carry some highly volatile nitroglycerine they hope to use to free the trapped climbers, they must overcome various difficulties and perilous incidents while trying to reach them before time runs out.