During World War II Stephen Neale is released into society after spending two years in a mental hospital. Before heading to London, he stops at the village fête, where he wins a large cake. It's clear that something valuable was in the cake as it is forcibly taken from him on the train. He's certain that something, perhaps a crime, occurred and begins an investigation. He comes to believe that a Nazi spy ring could be at work, but has difficulty getting anyone to believe him.
—garykmcd