A group of agents of the U.S. Office of Strategic Services (a forerunner of the Central Intelligence Agency) is sent to German-occupied Italy during World War II to knock out the German-held Italian railroad system. In accomplishing this mission, most of them are killed because of an inside betrayal.
After the war, one of the survivors, Captain Webster Carey (Alan Ladd), resolves to find the traitor. Captain Carey returns to Orta, near Milan, to find out who betrayed his World War II O.S.S. team and caused the deaths of several villagers. Much to his surprise, his old love Giulia (Wanda Hendrix), whom he thought dead at the hands of the Nazis, is alive and married to a powerful Italian nobleman, Barone Rocco de Greffi (Francis Lederer). The villagers are unfriendly, but Carey persists in his clandestine efforts to flush out the traitor, who turns out to be de Greffi.
The film was based on the serial Dishonored. Jonathan Latimer was originally announced as screenwriter and the stars were to be Ray Milland and Alida Valli, with the title to be After Midnight.[3]
The fictional film seems to recall real places and real events: the setting in Orta San Giulio, Lake Orta, Villa Castelnuovo and the Major of the United States of America Army William H. Holohan who on the night of the 6th December 1944, Commander of a secret mission behind enemy lines in charge of coordinating allied supplies to the partisan formations, with a secret refuge in a difficult to reach Villa and with a suitcase with a lot of money destined for the partisan formations, mysteriously disappeared in San Maurizio d ' Opaglio on Lake Orta during a Nazi attack; his brother who in the following years investigates, listens to witnesses, writes letters and one of these arrives in the hands of a Carabiniere who in turn investigates, collects elements until the confession of a murder by poisoning and with gunshots from fire, and the discovery of the body 5 years later, by order of the Partisan Chief Vincenzo "Cino" Moscatelli, as admitted by himself to Edward Bennett Williams and FBI later when he was Senator of the Italian Communist Party.
