WWII. Zyga, one of the Resistance soldiers in Kraków (Poland), is arrested by Gestapo. Soon later with new arrestings comes out that Germans must have received some new informations. Zyga is suspected to become an informator.
Young boxer studies with a kind, knowing manager, grooming him for the Olympics. He fights the lead boxer, has a brief fling, and gets jailed for beating up a group he feels laughed at him during the drunken spree. But he is rehabilitated and gets a crack at the Olympics where he wins.
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.
