Brahms x Reader - After the killing

Chapter 1 - Cole is dead

You are terrified. Terrified that Brahms is mad at you.
Mad that you broke the rules, you let someone in his home. His safe place. None of this would've happened if it weren't for you. You have to escape, right this second before he does the same thing to you.
You start running as fast as you ever have, through the dark halls. Brahms jumps out from the shadows in front of you, seemingly out of nowhere, startling the life out of you. You flee up the stairs in a panic, hearing Brahms steps closing in behind you. You stumble across the floor and throw yourself through a door, closing it with a slam behind you.
Young Brahms room. You look around for anything of help, something to break the window... And you spot a hole in the wall. Must be one of the secret tunnels! You have no time to hesitate so you rush over there, and start climbing the narrow stairs you come across in the tight dark space. Please let there be an exit, please let me get out of here alive you keep repeating inside your head. Please, please! You reach the top of the stairs and spin around in the dark, looking for somewhere to go.
You see a light shining from behind a hidden door, your only chance. You pull it open and step into a big, cluttered room. This... this is his hideout. It looks almost like a small apartment.
It smells fusty and stuffy in here. There's things everywhere. A fridge, microwave, a sink and mirror, a toilet and stairs to a second floor. There's canned food on the shelves along with bottles, jars and the meal boxes you were instructed by the Heelshires to freeze. There are string lights, watches hanging in twines from the ceiling, little plastic animals, a violin. Some plants, wooden beams covered with sheet music, tons of books, taxidermy... And something that looks like egg cartons all over the walls.
At the other end of the room you notice a bed, with something on it that at a first impression looks like a human! You breathe out when you realize it isn't an actual person, but a life size doll... Then it hits you. Your dress. The doll is wearing the one dress that you couldn't find before. Next to it lies a little package of handkerchiefs, and a crumpled up one that seems to have been used. Jesus Christ...! This is worse than disgusting. This is too fucked up! You turn around and spot a paper on the drawer next to the bed. A short letter. You rush through the hand-written words.

Our Dearest Son,
Words cannot describe our heartbreak as we leave you now.
We will not be back. We simply cannot bear to live with what we have allowed you to become.
The girl is yours now. She is yours to love and care for.
God forgive us all.
Love always,
Mummy & Daddy X X X

What the hell... cold shivers run down your spine and you back away, nearly knocking over a pile of books on a stool. They left for good? "The girl is yours now. She is yours to love and care for" ...?
It all made sense now.
Mrs. Heelshire whispering she was sorry in your ear as they left.
Mr. Heelshire acting so nervously and ridden with guilt.
The both of them speaking to "Brahms" about you behind a closed door.
Shit, shit...! This can't be. You hurry off and stumble up the stairs where you find another hole in the wall leading to a ladder. Looks like it's the only way out, so you take a deep breath and start climbing as quick as your feet can carry you, further down into darkness.
You find yourself once again in one of the tunnels, and you hear creaking somewhere. You stop for a moment and listen, holding your breath. You can't tell which way it's coming from and start to panic even worse than before. You can feel the walls closing in on you, the sound of your heartbeat thunders in you ears. You sneak around a corner quietly and try to walk as softly as you can, looking for any source of light or doors.
And then, at your left, you see it; an air vent hatch at the far end of a narrow passage obstructed with drain pipes. And at the same moment, now somewhere very close to you hear a loud creak.
"Y/n?" a childlike innocent voice calls out, just around the corner...