J. A. Darke 
Do Not Watch [PDF ebook] 

Having spent much of his childhood snooping around an antique store owned by his father, Sam Valentine is no stranger to encountering eerie objects. When he comes across an old VHS tape in the desk of a late horror movie director, Sam is curious. Its label reads: DO NOT WATCH. But for Sam and his best friends, Olivia and Bashiir, the temptation is too great. Soon after watching it, strange things begin to happen, sicknesses and dreams of the movie’s killer haunt them. Are the three friends imagining things? Or is there really an evil being lurking in the dark, seeking out the children who freed him?