When she joins her father and several others investigating a strange whirlpool and possible sunken treasure ship off the coast of Baja California, thirteen-year-old Kate is drawn into a centuries-old conflict between Merlin and the evil Vagar.

The twins have to find out who wants to stop their dog Clue from performing as a circus clown.

Three marshmallow-mining prospectors have been scared away from their mine by a claim-jumping, snowball-throwing monster. In a wild volcanic wilderness like Jelly Jungle, what kind of monster can the twins be up against?

Twins Mary-Kate and Ashley investigate when they visit a zoo where the animals act in a very strange manner.