In a small town in Massachusetts, a group of friends, fascinated by the internet lore of the Slender Man, attempt to prove that he doesn't actually exist - until one of them mysteriously goes missing.

Friends hiking the Appalachian Trail are confronted by 'The Foundation', a community of people who have lived in the mountains for hundreds of years.

After viewing a strangely familiar video nasty, Enid, a film censor, sets out to solve the past mystery of her sister's disappearance, embarking on a quest that dissolves the line between fiction and reality.