In the center of the lyrical and dramatic narrative is the frontline fate of one of the millions of ordinary soldiers of the Great Patriotic War - sapper Fedor Chaklun and his four-legged assistant - a specially trained sheepdog named Rumba. With the help of Rumba Fedor discovers a mined section of the road and warns about it senior in rank - junior lieutenant Svetlana. But the girl, carried away by flirtation with the lieutenant colonel, forgets to block the road, and a Soviet tank explodes on the mine. Fyodor, in love with Svetlana, takes the blame...