The story follows four young children who all suffer from different phobias. They are sent to a secretive school that will help them overcome their fears, if they can survive the treacherous final test. Producer Graham King first acquired the rights in 2007, before the first book was published. The rights expired, with Red Crown Productions taking the project to McG's Wonderland company. McG is not attached to direct, although he will have the first option.
Daniel Mackey is writing the adapted screenplay. He previously wrote for the web series Aim High, which McG produced. Mary Viola and Scott Fischer are producing for Wonderland, with Daniela Taplin Lundberg, Daniel Crown, and Riva Marker producing for Red Crown. No production schedule was given.