Dmitry Kolesnikov's wife Olga receives an excerpt of his farewell letter from officials 2 months after the behemoth submarine "Kursk" of the Russian Navy sinks in the Barents Sea in August 2000. But the letter may contain more clues to how this seemingly invincible war machine perished so mysteriously and Olga starts her quest to find some answers to the tragedy that turned her life upside down.