The Ironwood Tree (Spiderwick Chronicles Series #4)

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 is killing off all the plants and animals fo…