Spiderwick Chronicles - The Seeing Stone

The Seeing Stone was published alongside the first book in May 2003. After the Grace children ignore Thimbletack's warning to destroy the Guide, Simon is abducted by a group of invisible goblins who live in the woods surrounding the house. Thimbletack leads Jared to a "seeing stone", which gives him the ability to see faeries, called the Sight. After they narrowly avoid being captured by the goblins, Mallory and Jared go searching for Simon. On their way through the forest, they encounter a troll residing in the river, but are protected by the daylight, and manage to find the goblin camp. While rescuing Simon, they meet a hobgoblin named Hogsqueal who convinces them to help him escape in exchange for his help in rescuing Simon. Hogsqueal additionally offers to spit in their eyes, which gives them the Sight even without the stone. Now reunited with Simon, they flee and lead the goblins back to the troll, tricking him into letting the children escape in return for leading the goblins to him to eat. They go back to the empty camp and release the rest of the goblin's victims and take an injured griffin back to stay in the carriage house on their property. After confronting their mother, they discover that, since Jared had taken the stone from Thimbletack forcibly, he has again reverted to his mischievous ways..