Two strangers, Jerzy and Marta, accidentally end up holding tickets for the same sleeping chamber on an overnight train to the Baltic Sea coast. Also on board is Marta's spurned lover, who will not leave her alone. When the police enter the train in search of a murderer on the lam, rumors fly and everything seems to point toward one of the main characters as the culprit.
Based on a true story of Polish submarine "Orzel" (The Eagle): September 1939, "Orzel" is coming to Estonian neutral harbor in Tallin. Under pressure from Germany Estonians have intern the ship. Commander Grabinski decides to escape to England through the Baltic Sea, without any maps that has been confiscated and with only small amount of fuel on board.