Gargling with Tar by Jachym Topol
Czechoslovakia, 1968. The Soviet troops have just invaded the country and, for the young orphan Ilya, life is suddenly turned on its head. At first there is relief that the mean-spirited nuns who run the orphanage have been driven out by the Communists, but as the children are left to fend for themselves, order and routine quickly give way to brutality and chaos, and Ilya finds himself drawn into the violence, both committing murder in order to save his best friend and forced to witness the death of his disabled brother. When the troops return, the orphans are given military training and, with his first-hand knowledge of the local terrain, Ilya becomes a guide to a Soviet tank commander, leading him ever deeper into a macabre world of random cruelty, moral compromise, and lasting shame.