In the midst of World War II, a diverse group of survivors from a torpedoed passenger ship find themselves adrift in a lone lifeboat in the North Atlantic. As tensions swiftly rise, the group includes a journalist, a wealthy industrialist, a nurse, and various crew members, each bringing their personal prejudices and social backgrounds into the confined space. The situation becomes even more complicated when they rescue a German U-boat captain from the water, sparking distrust and leading to moral and ethical dilemmas about his intentions and their survival.

Struggling against the elements, the survivors must confront their deepest fears and biases while deciding whether the enemy among them can be trusted. Resources are scarce, and decisions carry life-or-death consequences as they contend with hunger, thirst, and the perpetual threat of the vast ocean's indifference. Suspense builds as alliances form and fracture, pushing each individual to their psychological limits. The group's dynamics shift continuously in their desperate fight for survival.