The Ironwood Tree

Spiderwick Chronicles #4 

First, a pack of foul, smelly goblins snatches Simon. Then a band of elves tries to trap Jared. Why is the entire faerie world so desperate to get their hands on Arthur Spiderwick’s Guide? And now that the Guide has mysteriously disappeared, will the Grace kids finally get a moment of peace? Don’t count on it.

At school, someone is running around pretending to be Jared. To make matters worse, Mallory has vanished, and something in the water is killing off plants and animals. Clues lead to the abandoned quarry just outside town, now overrun by dwarves. Meanwhile, the faerie world is abuzz: a creature with ambitions to rule the world has offered the dwarves a gift to join him—a queen.