Lauren Bailey has disappeared. Her classmates are horrified. The girl's parents and police cannot find her. Only Matt Barker, Lauren's childhood friend, has any idea where she might be. He sees frightening dreams: a black sky, a dark forest and a strange gloomy silhouette between the trees... He knows that this is the figure of Slender Man. Could Slender Man have taken Lauren? The solution is developing piece by piece: from Matt's diary entries, online correspondence, newspaper headlines and dreams . Fiction or truth, nightmare or reality? Will Matt Barker be able to find out the truth before Slenderman finds a new victim?