Based on the Eric Ambler novel entitled "Epitaph for a Spy," this is the story of a medical student on the Riviera during the Summer before WWII begins. A refugee from Austria, he has been photographing wildlife. When the film he develops contains secret installations, he must prove that he is not a German spy or be deported. With the police and help from a romantic interest that pops up along the way, he has to try to flush out the real spy to clear himself. Critical reviews were mixed, though Mason did an admirable job on his character.