Navy Commander Alan Roberts is assigned to lead an expedition to Little America in Antarctica to investigate reports of a mysterious warm water inland lake discovered a decade earlier. His helicopter and its small party, including reporter Maggie Hathaway, is forced down into a volcanic crater by a fierce storm. They find themselves trapped in a lush tropical environment that has survived from prehistoric times.
Beloved priest Father Thomasino is murdered in a San Francisco alley, and the police have few clues. But traffic cop Joe Martini becomes obsessed with finding the killer; he suspects Sylvio Malatesta. Ordered off the case, Joe turns in his badge and investigates alone. Soon he is a close friend of the Malatesta family, all delightful people, especially lovely cousin Anna. Uncertain whether Sylvio is guilty or innocent, Joe is now torn between old and new loyalties.
Ma and Pa do their bit to hook lumberman Brad Johnson up with spoiled socialite Sally Flemming. Ma teaches Sally how to behave like a hick so she'll be compatible with Brad.