On January 27, 1962, a concert at the Maly Theatre in Leningrad is interrupted by a gunshot and an ex-state prisoner is arrested.

At the police station, the mysterious gunman recalls the early summer of 1941… When the German army begins its invasion of Soviet Russia, four children are evacuated to the countryside: Maxim, the son of a senior Communist Party official; Pyotr, the son of writers; Anka, the daughter of a concert violinist; and Grigory, the son of a pilot that was executed for insubordination.

The farm where they are staying is attacked and the train that is supposed to take them to safety is blown to bits by German planes.

The four children must fight through enemy lines to get back to their families in Leningrad. But all that awaits them is the beginning of one of the most prolonged and destructive sieges in history. Two and half desperate years that will push their friendship -and their lives -to the limit.