WWII, 1945. There are fights for the city on the Danube. The river is mined by the Germans, and this fetters the action of our troops. In addition, a city with a million people was left without food. And downstream are Soviet food barges. The command instructs the reconnaissance group a difficult and dangerous operation — to obtain from the enemy a map of the mined sections of the river, which requires penetrating into the city captured by the Germans.