The Raven's Children: Yulia Yakovleva

Powerful historical fiction for fans of The Silver Sword and The Boy in the Striped Pyjamas.
Russia in 1938 is a place of great terror. Joseph Stalin is in charge. His Secret Police are everywhere, searching for anyone who might be his enemy. People have no idea who they can trust.
Seven-year-old Shura doesn`t know about any of this. He`s happy in his little home in Leningrad going to school in the mornings, playing with his best friend in the afternoon, fighting with his big sister, spending time with his Mama, Papa and baby brother Bobka.
Until one day everything changes.
Mama and Papa and Bobka disappear without a trace. The whispers of their neighbours are that Mama and Papa were spies, enemies of Stalin and so they have now been taken by something mysterious called The Raven. Desperate to reunite his family, Shura decides to hunt down The Raven, finding help in the most unexpected places but facing more danger than he has ever known . . .