Stuart Thaman 
For We Are Many [EPUB ebook] 

No one believes Fletcher Lee when he says he sees someone lurking in the shadows. Removed from his middle school for frightening the other children, 13 year old Fletcher is forced into psychotherapy where his visions are believed to be the result of a traumatic childhood experience. Pressured into reliving his worst nightmares, Fletcher’s torments grow until they can no longer be written off as mere hallucinations.
When Fletcher’s state deteriorates to the point of causing harm to his psychologist, Dr.Kendrick turns away from conventional medicine and discovers a much more troubling, supernatural answer. Without enough time to rescue Fletcher, Dr. Kendrick must make a choice: is she strong enough to risk her soul to find him?