Henry and three of his classmates encounter mind-bending ghostly terror when they volunteer for a weekend study with their psychology professor in the haunted 'Mad Hatter' mansion.

The kids are thrilled that Bernie has come back. But so has their old enemy Winston, who's about to kidnap the talented dolphin. Kevin and Holly must rescue their splashy friend before it's too late.

On their way home, Bong and Anna discover Kokey, an extraterrestrial whose spaceship exploded upon landing on earth. Without their parents' knowledge, the children keep Kokey at home.The three become the best of friends and Kokey ...