The Seeing Stone by Tony DiTerlizzi

Book Two of The Spiderwick Chronicles

In this enchanting tale, young Jared Grace discovers a mysterious stone that allows him to see a hidden world filled with fantastical creatures and magical beings. As he delves deeper into this secret realm, Jared, along with his siblings Simon and Mallory, must navigate the challenges and dangers posed by mischievous goblins and other mythical entities. The siblings' bond is tested as they strive to protect their family and uncover the truth behind the stone's powers, all while learning valuable lessons about courage, teamwork, and the importance of believing in the unseen.