The story is based on the real events of 1985. The team of a Russian polar icebreaker “Mikhail Gromov” discovered a giant iceberg. The ship came into collision while attempting to take cover from the weather and is forced to drift with ice along the Amundsen Sea coast. The crew of “Gromov” spent 133 days of polar night trying to find a way out of their icy trap. They have no room for mistakes; one wrong move and the vessel is crushed by ice.