After returning home from their latest adventure, Mallory, Jared, and Simon find Mulgarath, an ogre and leader the goblins, has taken captive their mother along with Uncle Arthur's field guide.

When the Grace children go to stay at their Great Aunt Lucinda's worn Victorian house, they discover a field guide to fairies and other creatures and begin to have some unusual experiences.

First a pack of vile, smelly goblins snatch Simon. Then a band of elves try to entrap Jared. Why is the entire faerie world so eager to get their hands on Spiderwick's Guide? And will the Grace kids be left alone, now that the Guide has mysteriously disappeared? Don't count on it… At school, someone is running around pretending to be Jared, and it's not Simon. To make matters even worse, now Mallory has disappeared and something foul in the water...

With goblins, trolls, and the house boggart all trying to get them, the Grace children turn to Great Aunt Lucinda for help.

When the Grace children go to stay at their Great Aunt Lucinda's worn Victorian house, they discover a field guide to fairies and other creatures and begin to have some unusual experiences.

When the Grace children go to stay at their Great Aunt Lucinda's worn Victorian house, they discover a field guide to fairies and other creatures and begin to have some unusual experiences.