American undercover agents in Rome during World War II try to thwart the Axis.

After the fall of Mussolini in 1944 Capt. Paul MacDougall and his radioman, Sgt. Joseph Contini, are smuggled into Nazi-occupied Rome to investigate enemy activities, though neither has had any training in espionage. They are met on the beach by Livio Massimo, an 11-year-old resistance fighter, who leads them to his father, Ciccio, leader of the Italian resistance. Massimo's daughter, Antonella, who is friendly with German officers, resents the intrusion of the American spies because the family is hungry, but she changes her mind when she learns that her sister, Rosalba, is pregnant and in need of a husband. Contini and Rosalba fall in love, and Massimo plans to announce their engagement at a feast, providing he can find enough food. Antonella innocently serves all but one of the carrier pigeons used by MacDougall to carry messages. Livio, trying to be helpful, replaces them with stolen German pigeons, which fly MacDougall's messages directly to the Nazis. Frantic, MacDougall sends insane, contradictory reports, but the surviving American pigeon carries one of these to the Americans at Anzio. The Americans decide to attack; Rome is liberated; Rosalba is married just as her baby arrives; MacDougall marries Antonella on the spur of the moment; and the lone American pigeon receives the Medal of Honor.