In 1942, a convoy of 35 civilian ships, carrying vital supplies from Iceland to the Soviet Union, faces deadly challenges in the Arctic. Despite Allied naval escort, catastrophic intelligence errors expose the convoy to relentless German air and naval attacks. In the brutal conditions, inexperienced civilian sailors fight for survival, with only 12 ships making it to their destination.

During a solo voyage in the Indian Ocean, a veteran mariner awakes to find his vessel taking on water after a collision with a stray shipping container. With his radio and navigation equipment disabled, he sails unknowingly into a violent storm and barely escapes with his life. With any luck, the ocean currents may carry him into a shipping lane — but, with supplies dwindling and the sharks circling, the sailor is forced to face his own mortality.