In the World War II era, Geoffrey Pyke was described as one of the world's great minds. An inventor, adventurer and polymath, he was an unlikely hero of both world wars. He earned a fortune on the stock market, founded an influential pre-school, and is seen as the father of the U.S. Special Forces.

In 1942, he convinced Winston Churchill to build an aircraft carrier out of reinforced ice. He escaped from a German WWI prison camp, wrote a bestseller, and aided Republicans in the Spanish Civil War. He even launched a private attempt to avert the outbreak of the Second World War by sending into Nazi Germany a group of pollsters disguised as golfers.

And he may have been a Russian spy.

70 years after his death, Henry Hemming reveals Pyke's astonishing story in full: his brilliance, his flaws, and his life of adventures, ideas, and secrets.