I definitely enjoyed reading this book and wanted to know what happened next the entire time, but I was a bit let down by the ending. You spend the whole book wondering who this Mr Interested is that is stalking the main character, but when the big reveal comes it kinda feels ridiculous and unbelievable. Why would this character bother going through all this rather than present themselves to the main character and explain their relationship to her? It all becomes a bit too farfetched and loses the impact the rest of the story had. Also, the conclusion is up in the air and you don't know what happens to any of the characters after the big showdown. Did Richard survive? Will her brother get better? Who knows. I did enjoy the premise being built around the Slender Man stabbing though, stories are always creepier when they're based on real events.