Wealthy industrialist Robert Talbot arrives early for his annual vacation at his luxurious Italian villa to find three problems lying in wait for him. Firstly, his long-time girlfriend Lisa Fellini has given up waiting for him to pop the question and has decided to marry another man. Secondly, the major domo of his villa, Maurice Clavell, has turned the estate into a posh hotel to make some easy money while the boss isn't around. And, finally, the current guests of the "hotel" are a group of young American girls trying to fend off a gang of oversexed boys, led by Tony, who are 'laying siege' at the outer walls of the villa. Talbot, to his own surprise, finds himself becoming an overprotective chaperone.

Successful and well-liked, Dr. Noah Praetorius becomes the victim of a witch hunt at the hands of Professor Elwell, who disdains Praetorius's unorthodox medical views and also questions his relationship with the mysterious, ever-present Mr. Shunderson. Fuel is added to the fire when Praetorius befriends young Deborah Higgins, who has become suicidal at the prospect of having a baby by her ex boyfriend, a military reservist who was called up for service in the Korean War and killed in action.

Several survivors of a torpedoed ship find themselves in the same boat with one of the men who sunk it.