During the Korean War, Italian nurse Virna Lisi falls in love with two American fliers, Tony Curtis and George C. Scott. Lisi marries Curtis after he convinces her that Scott has been killed in a plane crash. She soon discovers Scott is alive, but remains happily married to Curtis until Scott re-enters their lives 14 years later.
When Singapore surrendered to the Japanese in 1942, the Allied POWs, mostly British but including a few Americans, were incarcerated in Changi prison. Among the American prisoners is Cpl. King, a wheeler-dealer who has managed to establish a pretty good life for himself in the camp. King soon forms a friendship with an upper-class British officer who is fascinated with King's enthusiastic approach to life.
Scientist Jim Grayam saves his boss' wife from suicide but then falls in love with her.
When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save one of the astronauts Colonel Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.
Bedelia Carrington is living happily, it appears, in Monte Carlo with her husband Charlie Carrington. But a cultivated young artist, Ben Chaney, begins probing into her past with curious concern. Chaney, who is really a detective, learns that Bedelia's obsession for money has led her, in the past, to husband-poisoning for the insurance money.