Stauffenberg, Olbricht and the plotters launch Operation Valkyrie. The army moves in to seize power, troops surround the government quarter in Berlin, and Joseph Goebbels is arrested. But things start going wrong pretty much immediately and far away in East Prussia the Nazi fightback begins.

In the New Mexico desert, a secret team of scientists is working flat out to develop atomic bombs. It's the most important American military project in history. But one of those scientists lives a double life. Klaus Fuchs has decided to betray his country and share America's most secret technology with the Soviet Union. But is he the only person who has turned traitor?