An accident at sea cripples a Royal Navy expedition 200 miles from finding the Northwest Passage, forcing its captains to make dire choices.

After a long winter trapped in the ice, scouting parties are sent out in search of open water. One of the teams makes a frightening discovery.

A cunning attack on the ships proves the men are not battling an ordinary bear and that the region's Inuit culture may hold a key to their survival.