A psychologist must revisit his childhood fears in order to help a disturbed teen find the truth behind his encounters with a mysterious supernatural being known as "Slender Man."

“In order to help mentally disturbed student, a (school) psychologist must confront his own personal demons to prevent the mysterious “Slender Man” from taking his next child victim.”

As Karel said, your protag (psychologist) has to have some sort of character arc, so you may want to start him off as timid and not willing to face his own personal fears/repressed memories. When given the ultimate option of coming forth to save another – this time, a teenager – he knows what he has to do to save him. You have the protag, the antag, the goal, the stakes and the genre pretty clealry depicted (as long as it’s NOT a rom/com!). What the story lacks is the real “hook”; what separates this from other movies of the same genre (The Butterfly Effect”, “Mothman” and others)? This is were concept development is so important. On the surface, it mind sound like a cool story to write, and it does. Ultimately, yo’ll want to DO something with it, and without a “hook”, it’s an even harder hill to climb.

Hope this was helpful.

(Geno Scala, “sharkeatingman” – judge)