"After the tragic death of their father, Emily and Navin move with their mother to the home of her deceased great-grandfather, but the strange house proves to be dangerous. Before long, a sinister creature lures the kids' mom through a door in the basement. Em and Navin, desperate not to lose her, follow her into an underground world inhabited by demons, robots, and talking animals. Eventually, they enlist the help of a small mechanical rabbit named...

After chasing the monster that kidnapped their mother, Emily and Navin find themselves in a magical world of man-eating demons and shadowy enemies, where they must learn to control an amulet given to them by their grandfather.

Copper is curious, and Fred is fearful. And together boy and dog are off on a series of adventures powered by Copper's limitless imagination. The two friends have a knack for getting into all sorts of odd situations, but Copper's good cheer always smoothes the way--and Fred can usually be won over if there's food involved.