It was Mark Twain who said that “Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities; truth isn’t”. Never has this held true more than in the case of Eddie Chapman, a figure whose story is so impossible, that MI5 stated that his tale was “different. In fiction it would be rejected as improbable”. In Agent Zigzag, Ben Macintyre has woven together the threads of a story which brings an entirely new level to the word ‘unbelievable’. It could be a blockbuster Hollywood spy film, complete with near constant explosions. But it’s not-because it’s all true, Chapman was probably the most successful British double agent in the war, and one of the best in history.