The first night, I dismissed it. It was exactly 8:00 pm when three sharp, deliberate knocks echoed from my front door. I had just settled into my worn armchair, the evening paper still crisp, in my hands. I walked to the door, peered through the peephole, and saw nothing but the empty porch, the street lights casting long, lonely shadows. I figured it was some neighborhood kids prank and went back to reading.

The second night, the knocks came again. 8 pm on the dot. I was in the kitchen making tea. This time, a prickle of unease ran down my spine. I hurried to the door, flinging it open. The porch light illuminated the porch and the small patch of lawn beyond, revealing only the gentle rustle of leaves in the wind. The air felt colder than it should have been. I stood there for a long moment, the warmth of my tea forgotten in my hand. I told myself it was just a coincidence.

By the third night, a sense of dread had set in. I was waiting. The clock on the wall ticked loudly in the silent living room. 7:59 pm. I held my breath. 8:00 pm. Knock. Knock. Knock. The sound was so crisp, so real, it seemed to vibrate through the very walls of the house. I didn't rush this time. I moved slowly, deliberately to the door. I didn't even bother with the peephole. I just put my hand on the knob, my heart pounding in my ears, and pulled it open.

And there, hovering in the space where a person should have been, was a faint, shimmering outline of a hand. It was translucent, like a wisp of smoke, and it hovered for just a moment before dissolving into the night air. The cold air rushed in, and I slammed the door shut, locking it with a trembling hand.

Every night after that, the knocks returned. Every night at 8 pm. I never opened the door again. I would sit in my armchair, the soundproofing of my old house barely muffling the insistent, rhythmic knock, knock, knock. I don't know what it was. A ghost? A warning? I only know that the space on the other side of that door was not empty and I had no intention of ever finding out what was on the other side of it.