One of the most surprising phenomena in publishing this year has been the success of a novel, Alone in Berlin, written over six decades ago.

The book follows the story of an ordinary couple, Otto and Anna, who mount a campaign against the Nazi regime by leaving postcards denouncing Hitler at strategic points around the city.

What does the book tell us about the nature and scale of German resistance during World War II, and about modern Germany's relationship with its past?

Broadcast on Wednesday 26 May 2010.