Sussex, England. 1929. Mydworth is a sleepy English market town just 50 miles from London. But even in this idyllic spot, crime is never far away. Luckily, the young and adventurous Sir Harry Mortimer has returned to Mydworth from his diplomatic post in Cairo with his unconventional American wife, Kat. And between them they are a match for anything - even murder. DEADLY CARGO Mydworth's Excelsior Radio Company is world-famous for its expensive radio-phonographs. But suddenly the Excelsior delivery lorries start being hijacked, and the very future of the company is in doubt.

Is this just about stolen radios - or is there something more secret and dangerous going on? When Harry and Kat are brought in to help, they decide to go undercover to solve the crimes and soon discover there are many more secrets to this mystery than meets the eye.