When the Russian submarine K-141 Kursk left for a maneuver of the Russian Northern Fleet in the Barents Sea on August 10, 2000, there were 118 crew members on board. On the second day of the exercise, a huge explosion leads to a catastrophe. The damage is so severe that the Kursk sinks to the seabed. Of the crew, only 23 men, including Lieutenant Captain Mikhail Kalekov, can save themselves in an intact section of the boat. While the Russian government refuses to provide any international aid for fear of espionage and a loss of reputation, the relatives of the crew members, especially Kalekov's wife Tanya, are fighting for clarification. Finally, the British Commodore David Russell also offers his help. But the Russian government remains stubborn and an unprecedented fight for life and death begins for the survivors.