It was obvious they were dealing with a professional - the killing was vicious and clever. William Carter, managing director of a firm carrying out secret work for the Admiralty, was found dead in his factory's enameling oven. He left behind him a wide choice of suspects - and the risk of a major security leak. Why had Carter sent urgent messages to his attractive wife and his business partner just before his murder? Had he known that his life was in danger? Thane and Moss, assigned to this most bizarre case, find some of the answers in a booby-trapped building - but the rest of the truth almost comes too late. . .