Carrie Stetko (KATE BECKINSALE) is a federal marshal who took a post at a U.S. research facility in Antarctica to get as far away from a troubled past as possible. There, she serves as the sheriff of sorts, all as pilots such as Delfy (COLUMBUS SHORT) and Russell Haden (ALEX O'LOUGHLIN) fly researchers, geologists and the like back and forth between distant work locations.
Having had enough of her line of work, Carrie is about to resign and return to the States, but that's before she, Delfy and the station's resident physician, Dr. John Fury (TOM SKERRITT), discover a frozen body out in the middle of nowhere. Realizing the victim was murdered, Carrie is determined to solve the case, but has little to go on.
Complicating matters is that winter is quickly approaching, and base commander Sam Murphy (SHAWN DOYLE) is itching to get everyone off the continent before a big storm hits. Not everyone is headed out, however, as U.N. special investigations agent Robert Pryce (GABRIEL MACHT) shows up. He's not only interested in the murder, but also in something several geologists were searching for buried somewhere under all of the ice.
That arouses Carrie's suspicions, but when a masked assailant tries to kill her and attacks others, she realizes this isn't a normal murder case. From that point on, and racing against the clock before the station is evacuated, the marshal tries to get to the bottom of what's occurring.