This story about two great men combines fact and fiction. They are Lionel Crabb, a Second World War hero who, through his exploits as a frogman, was awarded the OBE and George Medal, and Maitland Pendock, an obscure 'businessman' with a love of the arts, who moved in the shadows and served the wartime Ministry of Information as their link to the Secret Intelligence Service — MI6. When Crabb disappeared in 1956 while diving under a Russian warship in Portsmouth, England, Pendock became the focus of the Security Service because of Crabb's connection to the head of the Royal Navy — Lord Mountbatten. It had been a great adventure but, in the end, they knew too much.