In the years following World War II, Tommy Flowers walked into the Bank of England to apply for a business loan to build a civilian electronic computer, only to be rejected by a banker who claimed his invention was scientifically impossible. Due to the strict constraints of the Official Secrets Act, the working-class telephone engineer was legally forbidden from pointing out that he had already built ten of these "impossible" machines to crack Nazi codes and save millions of lives. Born in 1905 to a Poplar bricklayer, Flowers bypassed traditional academic pathways, completing a grueling General Post Office (GPO) engineering apprenticeship while taking university evening classes. Stationed at Dollis Hill, he focused on automating long-distance telephone routing using thermionic valves (vacuum tubes), uncovering the crucial, non-intuitive insight t ...