Cloak and Dagger (1946)

WWII. The OSS has received incomplete intelligence that the Nazis are in the throes of a nuclear bomb program. Colonel Walsh of the OSS believes that they require someone with more experience in the science to assist in this matter, recruiting his old friend,physicist Dr. Alvah Jesper, who is involved in the Manhattan Project. They discover that two of Jesper's mentors, Drs. Lodor and Polda, are part of two separate teams for the Nazis, they who are probably working against their will. They have to discover what the Nazis are using to force the two to work for them to diffuse the separate situations and bring both back to safety. With Polda, they discover that he is working in Italy, Jesper, teaming with the Italian resistance using a cover of being a scientist from a German institute, who is to be part of the field unit to extract Polda from his situation. In the process, Jesper may encounter two issues for which he is ill-prepared: that he would be involved in typical espionage, including kill or be killed; and that he would fall in love with one of the resistance fighters, a young woman named Gina, though both are aware that their romance will most likely be fleeting because of their work and the war--that is, if they even survive their current mission.