Achluophobia.

Kysa Bronte has Achluophobia, the abnormal fear of the dark, or so all the professionals say, but her instincts and the evidence say something entirely different.
At first she could handle it, but now something has drastically changed. The monsters that have been hiding in the darkness around her have grown bolder and more dangerous with the arrival of a being a lot more powerful.
That something comes in the form of a man and when he finally reveals himself, Kysa's life is changed forever.