A whale terrorising the monsters while they try to surf turns out to be engaged in a long-standing battle of wills with Dr. Knutt. When the whale swallows Dr. Knutt and Dean, Jan and the other monsters must fight to free them. Inside the whale, Dr. Knutt has made a friend even more dastardly than he is. Can Jan get her brother back and rid Monster Beach of the whale or can Knutt's new friend figure different a way out?