You know, when you're a kid, summer feels like it lasts forever. For me and my best friend Leo, the whole world was my backyard. It was this huge, green kingdom with a giant oak tree that was our fortress. But every kingdom has its forbidden place. Ours was the door. It was set into the old red brick wall at the very back of the property. Just a small, wooden door, barely four feet high, sealed with a padlock so thick and rusted it looked like a fossil. My dad said it was an old root cellar, long since filled in. He told me it didn't go anywhere. But Leo and I, we knew better. We felt it. We’d dare each other to run up and touch the cold, splintery wood. We’d press our ears against it on hot afternoons, the brick warm on our cheeks. Most of the time, it was just silence. But sometimes, if you held your breath and listened real close, you could hear it. A faint, slow dripping sound coming from the other side. Drip... drip... drip.