Judy regrets that she is leaving Farringdon for a vacation in the Thousand Islands just as life in Farringdon gets interesting. The police are on the trail of counterfeiters, but Judy won't be around to help them. Excitement does follow Judy, however, when she impulsively purchases seven Indian masks at an auction. Judy learns that the masks are rumored to be cursed and that misfortune befalls whomever owns the monster heads. At first Judy refuses to believe the nonsense, but after the young people arrive at camp, the heads begin to appear and disappear and change location within the storage box. Mysterious sounds are heard at night. The monster heads appear to be alive! As with all mysteries, there is a logical explanation for the movement of the monster heads, and Judy's search for the solution proves to be more exciting and dangerous than she could ever have imagined.