Barents Sea, August 12th, 2000. During a Russian naval exercise, and after suffering a serious accident, the K-141 Kursk submarine sinks with 118 crew members on board. While the few sailors who are still alive barely manage to survive, their families push for accurate information and a British officer struggles to obtain from the Russian government a permit to attempt a rescue before it is late. But general incompetence are against all their efforts.

An explosion on a nuclear-powered Russian submarine kills most of the men aboard and causes the few survivors to huddle in waterlogged and oxygen.