The Stonekeeper (Amulet, Book One)

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