An American secret agent, on the trail of a vanished scientist, must recover the scientist's revolutionary secret formula before the enemy catches up with his quarry first.
Prudence resigns from her teaching position after being criticized for giving a student her copy of a romance novel. She sails for Italy, takes a job at a small bookstore in Rome, and meets Don, who has just broken up with his girlfriend. Prudence and Don tour Italy together, and romance naturally follows.