Childhood friends Dan Walker (Kevin Zegers) and Joe Lynch (Shawn Ashmore), along with Dan's girlfriend Parker O'Neill (Emma Bell), spend a Sunday afternoon at a New England ski resort. Not wanting to pay full price for three ski lift tickets, Dan convinces Parker to bribe the ski lift attendant, Jason (Ed Ackerman), to let them all on the ski lift. On the way up, the ski lift shuts down, but starts back up again shortly. After spending all afternoon watching Parker fall over herself because she cannot snowboard, the guys are eager to take one last run down the mountain before they go home. However, it is now evening, and the ski resort decides to close early because a storm is moving in.
The friends remind Jason of the bribe and convince him to let them on the ski lift one last time. At this point, the resort is almost deserted. Before the group gets all the way to the top, Jason is called into the boss's office and is replaced by a co-worker, Rifkin (Adam Johnson). As Jason leaves, he tells Rifkin that there are only three skiers left and then the ski lift can be shut down. Another set of three skiers comes down the mountain. When Rifkin sees them he shuts down the ski lift, stranding them in their ski lift chair far above the ground.
The friends are first annoyed; they assume that there's another technical difficulty with the ski lift. A few minutes later, however, the lights go out, scaring the three skiers. Night has come and a snow storm moves in. After a while, a snowcat comes along and it seems as if the driver, Cody (Kane Hodder), is about to see them. However, at the last second, Cody is called back to base. After several hours, the friends realize that no one is coming to get them and that they could be stuck up there all week, as the resort is closed on weekdays. Parker then loses her right glove while smoking. Dan realizes he has no choice but to jump from the ski lift chair and get help, as they will not survive up there in the bitter cold until Friday.
Dan jumps off the lift onto a hard section of the ski path and suffers a compound fracture in both of his legs. Later on, he is approached by a wolf who growls at him, but Parker throws her snowboard at it and it runs away. Joe, now fearing for Dan's safety, decides to climb up and traverse the ski lift cable so that he can get to a chair that is closer to the ground. However, after traversing a few feet, he returns to his chair, his hands cut, and holds Parker, preventing her from watching the scene below. Dan has now been surrounded by a pack of wolves who devour him, horrifying Parker and Joe.
In the morning, Parker wakes up with her right hand stuck to the ski lift safety bar which she has grabbed in her sleep. She painfully pulls it free, losing skin in the process. In addition, she has developed a bad case of frostbite on her face. After a few hours, Joe climbs up, traverses the ski lift cable, severely cutting his hands in the process, and this time safely climbs down the ladder of a support pole two chairs back. At the same time, Parker's ski lift chair begins tipping as it has started to loosen from its supporting cable. After fighting off a pair of wolves using a ski pole, Joe slides down the mountain on Parker's snowboard as the wolves chase after him.
Another night passes and no one has shown up to help Parker. She now realizes that something has happened to Joe and, the next day, she begins to attempt a jump down herself, but the bolt holding the lift chair fails and the chair drops some twenty feet but is caught by a supporting cable. Parker jumps down, now from a fairly safe height, but is injured after the lift chair falls on her ankle. Parker then alternately slides and crawls down the mountain, pausing when she sees a streak of blood in the snow and is then approached by a wolf. After sizing her up, the wolf returns to the nearby pack, who are apparently finishing off Joe's remains. Completely traumatized, Parker makes it the rest of the way down the mountain to a nearby road. Eventually, a car appears and a man (Peder Melhuse) comes to her rescue. While on the road, the man calls the hospital and tells them that he had found a girl hurt outside of the ski resort. The film ends with Parker hearing Dan tell her "You'll be ok, baby. You're gonna be ok".