Astaroth is a demon, he possessed your mother and made her kill herself in front of you. He made sure to make each of your friends die, one by one. He has been watching you and giving you nightmares, but he has never attacked you directly. You decided to go to the asylum where your mother worked, that's where she was possessed, at least that's what you think.

The problem is that when you get there it is full of dead people, but the door locked itself and now you are locked in this asylum. Until one of the guards finds you still in front by the path he told you to follow. When you least expect it he grabs you by the waist and puts the knife to your neck, he won't hurt you, he can't, he just wants to threaten you so you don't run away from him.

"Now you are my home.." Astaroth says in your ear, he was using his human form, so you didn't notice it was him. If he makes you the slightest cut he will possess you completely, though he will not admit he wants your permission to possess you.