A mortal terror - James R. Benn

Two officers from the American troops stationed in Caserta, Italy, have been found murdered. The Mos are completely different and it seems like the officers had no connection to each other except for one frightening fact - each body was discovered with a single playing card: the lieutenant, the ten of hearts; the captain, the jack of hearts. The message appears to be clear: if the murderer is not apprehended, the higher ranks will be next. Billy is sent to Italy for the investigation, which grows increasingly sinister...