One summer day, when I was thirteen, I went into a haunted house with my friends on a dare. We rode our bikes four abreast on empty back roads, making up our own ghost stories and romances and adventures because we were bursting with the possibility of it all.

The house was in the shape of an octagon, and it was set way back off the road, so you’d have to know it was there to find it. We rode around to the back of the house and went in through the summer kitchen. As soon as I crossed over the threshold, I felt the residue of something that had been left behind. It was like walking into a cold patch of water. I don’t know if there were ghosts or spirits in that house, but there was some kind of energy. It felt both abandoned and alive.

I only stayed for a few minutes and wasn’t brave enough to wander past the first room. Right as we were leaving, I tore off a strip of wallpaper and put it in my backpack. The pattern had faded to a yellowish-brown, and it was thick with several generations of wallpaper stuck together, but it came off easily and felt delicate in my hand.

We ran out of that house shrieking and laughing, suddenly wild with release and adrenaline, and in my joy, I forgot about what I had slipped into my bag.

That night I found it. It was from that house, and whatever was there was also seeped into this paper. And now it was in my bedroom.

I had to get rid of it, but how? I put it under my bed, then I moved it between the pages of a book that I stuffed in the back of my closet, then I hid it downstairs. Nothing worked. No matter where I hid it, I couldn’t get rid of the feeling that the house—what was in that house—was attached to me now.

The next day I put it in a plastic bag, tied a tight knot, put that in another bag, tied another knot, and dropped it in the public garbage can at the local swimming pool.

Reading this now, it all sounds ridiculous; nothing more than the overwrought imagination of a teenager, and maybe that’s all it was. But I’ve never forgotten it. And when I started to write this book, before I even knew what the story was going to be, I had a picture of four girls on bikes standing outside a haunted house trying to decide if they were going to go in.

Real fear lives inside of us. The house was empty and creepy in all its shadowed corners and its brokenness. But the fear I felt – a fear I have never forgotten – it came from me.