The terror begins with a phone call in the night. A little boy has been injured, hit by a car. Hundreds of miles away his frantic mother, Diane Hastings, tries to reach him by the earliest flight. It is a holiday weekend and no seats are available. In desperation she turns to her former lover, Travis, an amateur pilot.

That same night, shots ring out in the city. A teen-age girl falls dead, victim of a restaurant holdup. The bandit, fleeing on foot, disappears. The next morning, when Diane, Travis, and his young daughter Shelley embark on their trip upstate, they are joined by a stranger who begs for a ride to reach his sick wife in Montreal.

Over the frozen Adirondack wilderness, the plane is forced down. Diane and Travis, both injured in the crash, are left for dead. Shelley is taken hostage by the stranger. The temperature plummets and a snowstorm begins, making rescue impossible. With Travis in danger of dying from his injuries, Diane must do something. But what? The stranger, armed and vicious, is out there in the snow, ready to strike at any moment.