John Thomas Straffen, England's longest-serving prisoner, was the first patient to escape from Broadmoor Hospital. He killed within hours. Prior to this, at his home in Bath, he was dismissed as an imbecile, a loner, a "child trapped in an adult's body". On the afternoon of Sunday July 15, 1951, John Straffen strangled 8-year-old Brenda Goddard as she picked flowers. Three weeks later he committed a similar murder before inadvertently confessing to the police. Faced with a serial killer with a mental age of 10, Straffen was admitted to Broadmoor Psychiatric Hospital. But on April 29, 1951, having spent only six months at the institute, he escaped during a meticulously planned bid for freedom that should have been impossible. During his six hours on the run, he murdered 5-year-old Linda Bowyer in an attempt to "annoy" the police. Winston Churchill, then Prime Minister, and his beleaguered government personally intervened to make sure that Straffen would never walk free. But was Straffen insane? Benefitting from previously unpublished documents, including classified government papers, author Gordon Lowe paints a vivid picture of a man whose crimes shocked a nation.