Six months after leaving the winter crew to hunker down and continue their research efforts in climate change, the summer crew of the Polaris VI Antarctic Research Station return to the base, concerned after weeks of radio silence. Led by Johan, the summer commander, the team finds the Winterers either dead or missing - including Johan’s wife Annika. Maggie, the base doctor and the only apparently survivor found, is suffering from shellshock and unable to recall what happened. With time ticking, Johan presses Maggie for news on Annica whose life is on the line. Slowly, Maggie begins to piece her story together, from how the events and murders transpired on the base - starting with the brutal murder of one of her teammates.
In the middle of the winter, a small group of scientists in charge of an international base in the Antartica during the long polar nights stops communicating with the outside world.
The summer team tries to find clues of what could have happened during the winter, unveiling a first possible suspect.