In 1941, a Spaniard walked into the British embassy in Madrid and offered to spy on the Nazis. The British turned him down. So he went to the Germans instead, pretended to be a loyal fascist, and got hired as a German spy. His plan was to lie to them for the rest of the war. It worked better than anyone could have imagined. His name was Juan Pujol García. Before the war he had tried his hand at running a chicken farm and a movie theater. He had no spy training. What he had was a deep hatred of both fascism and communism after the Spanish Civil War, and an incredible imagination. The Germans gave him a codename, invisible ink, money, and orders to go to Britain and recruit spies. He didn't go to Britain. He went to Lisbon, Portugal, and made everything up. Using a tourist guidebook, maps, magazines, newsreels, and a British railway timetable from the library, he wrote long, detailed reports about life in England. Military movements. Morale. Ports. He'd never been there. He made mistakes. He didn't understand British money. He once reported that dockworkers in Glasgow would do anything for a liter of wine. The Germans loved him anyway. Then British codebreakers reading German messages noticed something strange. The Germans were hunting for a convoy that didn't exist, based on a report from some agent in Britain they'd never heard of. The British went looking for this mystery spy. They found Pujol. In 1942 they finally took him on and brought him to London. Now he had real help. MI5 gave him the codename Garbo, after the actress, because they thought he was the greatest actor in the world. Together with his British handler, Pujol built a fake spy network for the Germans. It eventually had 27 imaginary agents. Each had a name, a personality, a job, and a backstory. A Welsh nationalist. A Venezuelan student. A Greek sailor. Some of them recruited their own imaginary sub-agents. When they needed to explain why one agent had gone quiet, they killed him off. They even put a fake obituary in a Liverpool newspaper. The Germans reportedly paid a pension to his widow. Who also didn't exist. Then came D-Day. Hours before the landings, the British let Pujol send a message warning the Germans that the invasion was coming in Normandy. It was timed so it would arrive too late to matter, but it made him look brilliant. Three days later he sent the most important message of his career. Normandy was a trick, he said. The real invasion was still coming, at Calais, led by a huge army under General Patton. That army was fake too. But the Germans believed him. German forces that could have been rushed to Normandy were held back near Calais for weeks, waiting for an attack that never came. The Germans were so grateful they awarded him the Iron Cross. A few months later, King George VI made him a Member of the Order of the British Empire. He's one of the only people known to have been decorated by both sides of the war. After the war, afraid of revenge from surviving Nazis, he faked his own death from malaria in Africa and disappeared to Venezuela, where he lived quietly running a shop. For decades the world thought he was dead. In 1984, a British writer tracked him down. Pujol came back to Normandy for the 40th anniversary of D-Day and met veterans who had landed on the beaches. Some of them thanked him.