It is a bleak winter in East Berlin, but not for Erika Nordern. Her life in the German Democratic Republic with her parents, both loyal civil servants, her meddlesome younger brother Paul, and her loving grandmother Omi, is good. As a promising young high jumper, she is also an outstanding candidate for a prestigious special sports school, if she can prove herself at the Berlin indoor championships.

Then one night a stranger knocks on the Norderns' door and announces he is Uncle Karl, Omi's long-lost brother, who everyone though had died during World War II. He is now a prosperous West German businessman and is visiting the country as a guest of the government. Although his appearance is exciting, it is also disquiting, as it stirs up the family's painful memories of the difficult years after the defeat of the Third Reich. In spite of Erika's fascination with this part of her family's past, and with Uncle Karl himself, she tries not to get involved, and instead forces herself to concentrate on her training and on winning the championship. It isn't easy, especially as Karl's arrival coincides with a succession of odd occurrences: Erika and her father are questioned by the police about a car accident they were never in; the Norderns discover that no one at the police station has heard of Lieutenant Werner, who made the inquiries; a co-worker of Herr Norden's mysteriously dies. And then, by chance, Erika makes a terrifying discovery that links all the pieces together.