1936. Europe is in turmoil. The Nazis have marched into the Rhineland. In Russia, Stalin has unleashed his Great Terror. Spain has erupted in civil war. In Berlin, a young Englishwoman evades the Gestapo to deliver vital papers to a Jewish scientist. Within weeks, she is found dead, a silver syringe clutched in her fingers. In an exclusive London club, a conspiracy is launched that threatens the very heart of government. When a renowned society couple...

The Nazis will kill to protect it. The Allies will die to uncover it. With the war on a knife-edge, the best weapon against the Third Reich may not be a weapon at all ... Autumn, 1941. The war is going badly for Britain and its allies. If Hitler is to be stopped, a new weapon is desperately needed. In Cambridge, professor Tom Wilde is approached by an American intelligence officer who claims to know of such a weapon - one so secret even Hitler himself...