August 2000: Mikhail Averin is a respected man in the Russian Northern Fleet. At the helm of the "K-141 Kursk", the most modern Russian nuclear submarine equipped with cruise missiles, he successfully steers the pride of an entire nation through the seas. During training on the high seas, a fatal chain of accidents occurs, resulting in explosions that damage the bow of the ship. The steering and instruments fail, causing the Kursk to sink uncontrollably into the depths. Many of the sailors are already dead; only a few survivors remain in the stern of the submarine, trapped at the bottom of the Barents Sea. With no light and no chance of communicating, the men are conserving their food and oxygen reserves as best they can, waiting exhausted, soaked and frightened for outside help. However, the Russian navy is not capable of such a rescue, as the only ailing salvage ship is unable to reach the survivors. Although the trapped people can be heard knocking desperately, they cannot be helped. British Commodore David Russell offers his Russian friend Admiral Gruzinsky NATO's help. However, Gruzinsky is forced by his superiors to turn down the offer. Meanwhile, Averin's wife Tanya and other families of the sailors are left completely in the dark about the situation of their loved ones. The relatives of those trapped try desperately to get through to the Russian navy command. But they are stubborn.