DiTerlizzi, Tony

Mallory and Jared attempt to rescue Simon from goblins using a magical stone which enables them to see things that are normally invisible.

Goblins, trolls, and the house boggart all try to get them, so the Grace children turn to Great Aunt Lucinda for help.

The Grace children discover a field guide to fairies in their Great Aunt Lucinda's old Victorian house that sends them on a fantasic journey into a world of elves, dwarves, and trolls.