The return of the original Mystery Incorporated to Crystal Cove sparks a race between the two groups to locate the pieces of the enigmatic planispheric disk, which will point the way to the cursed treasure buried beneath the town. As the fragments are gathered, it becomes clear that these two teams are not the only mystery-solving groups to have lived in Crystal Cove: many similar groups, always consisting of four humans and an animal, have existed throughout history. The secret behind their centuries-long connection will unveil the truth behind the curse of Crystal Cove. With extradimensional forces gathering in preparation and the time of Nibiru drawing near, the fate of both the gang's friendship and all of reality itself hangs in the balance.