The Wrath of Mulgarath is the fifth and final book in the Spiderwick Chronicles. It was written by Holly Black, illustrated by Tony DiTerlizzi and published at Simon & Schuster Books for Young Readers in September 2004.
The Grace kids return home from the quarry and find the house in ruins after Mulgurath had attacked it in search of the book. Thimbletack is saddened that he failed to protect the book and the house and decides to help the kids get it back. On the room Byron is chasing a goblin that turns out to be Hogsqueal who was forced to serve in Mulgurath's army. The kids find out from him that Mulgurath's base of operations is in the junkyard and he is planning to take over the world using dragons. Jared decides to return to the elves to seek the help of Arthur Spiderwick (who they have imprisoned there) he gives him information to defeat Mulgurath, but as he turns to leave the elves demand that once he has the guide back he is to give it to them. The group get inside the junkyard by posing as Hogsqueal's prisoners and manage to fend off the goblins and kill the dragons. Though Simon is traumatized for having to actually kill a living creature. The siblings infiltrate the palace of trash and find their parents being held captive but then Mulgarath who was posing as their father grabs Simon and Mallory and threatens to throw them out the window. Jared keeps him busy while Thimbletack ties a chain around Simon and Mallory before he drops them. Mulgurath reveals the guide is under his throne and Jared stabs him with Mallory's sword and he falls out the window. The chain saves Simon and Mallory and Mulgurath changes into a sparrow and is then eaten by Hogsqueal. Soon after Lucinda is back living in the newly repaired manor along with Byron and Hogsqueal as new residents. The Grace family go to give the guide to the elves, but as a reward for showing it can be used for good they are allowed to keep it. Arthur is reunited with Lucinda and makes the choice to leave faerie and turns to dust. They bid him a bittersweat farewell and return to the Spiderwick estate for more adventures.
- Table of Contents
- List of Full-Page Illustrations
- Letter from Holly Black
- Letter from the Grace kids
- Map of Mulgarath's Domain
- Chapter One IN WHICH the World Is Turned Upside Down
- Chapter Two IN WHICH an Old Friend Returns
- Chapter Three IN WHICH Jared Finds Out Things He Doesn't Want to Know
- Chapter Four IN WHICH Everything Goes into the Fire
- Chapter Five IN WHICH They Find the Meaning of "Here There Be Dragons"
- Chapter Six IN WHICH All Hell Breaks Loose
- Epilogue IN WHICH the Story of the Grace Children Comes to Its Conclusion