Celebrate the 20th anniversary of the international bestselling Spiderwick Chronicles with the fifth instalment in the adventures of the Grace children. 
Bruised and battered, having narrowly escaped the clutches of faerie world, Jared, Simon and Mallory return home to Spiderwick, only to find the mansion ransacked and learn that Mulgarath has made off with both the Guide and their mother!  
With only the help of Thimbletack, Hogsqueal, and Byron, the children now have to work out how to find Mulgarath, the guide and, most importantly, save their mother from the faerie world before it's too late . . .