In wartime Berlin a book critic, Thomas Rost, is pressured by top Nazis to locate the missing diary of HItler's deceased niece. He reluctantly takes on the job of finding the book, one with potentially explosive details on the Fuehrer, for personal reasons. As the bodies of people with a connection to the affair litter the winter streets of the German capital, it becomes clear that some in power would prefer the lost book remain hidden forever. How can Thomas survive the dangerous assignment?