The Second World War is over. The post-war Germany is divided into several responsibility zones. Still many Russian people languish in camps located in the American zone. Though former allies are in no hurry to let them off to the motherland, and even try to enroll some of them. The American intelligence agency gets to know that they've got a daughter of one of the West Germany cities commandant, whose brother is a famous soviet rocket engineering designer. They plan a crafty operation on the discrimination of the Russian colonel and introduction of the niece into the uncles design office. The Russian Intelligence service is also aware of the Americans interest in the designers works. The special department colonel Lartsev is coming from Moscow to Germany to prepare a reciprocal operation.
An old pickpocket named "Cardinal", during the days of the International Festival of Youth and Students, decides to gather old “personnels” to prepare small and large thefts from the festival participants. During the "conference" it turns out that a complete "personnel crisis" has come. The ensuing meeting with the former bootlegger — Senka-Moroz, who broke with his past and found happiness in his family and honest work, leads the Cardinal to confusion and mental confusion. A conversation with Professor Muromtsev, a terminally ill person who nevertheless cares about the fate of others, shock the "Cardinal" and he takes the first but decisive step towards a new life, breaking with the criminal world.
The accountant of the commodity base discovers a small mistake in the documents, as told by the manager of the base. That night, someone hacked and robbed a safe with accounting documents, and committed the killing of an accountant. The case for the search for criminals was entrusted to police commissioner Krechetov and lieutenant Kasyanov.