Agent Jack tells the incredible true story of Eric Roberts, a seemingly inconsequential bank clerk who, in the guise of “Jack King”, helped uncover and neutralize the invisible threat of fascism on British shores. Gifted with an extraordinary ability to make people trust him, Eric Roberts penetrated the Communist Party and the British Union of Fascists before playing his greatest role for MI5: Hitler’s man in London. Pretending to be an agent of the Gestapo, Roberts single-handedly built a network of hundreds of British Nazi sympathizers—factory workers, office clerks, shopkeepers —who shared their secrets with him. It was work so secret and so sensitive that it was kept out of the reports MI5 sent to Winston Churchill.