The old man had lived in the same house for over forty years, hidden away in a quiet corner of a forgotten town. No one knew much about him—just that he never left, never spoke to anyone, and always kept his windows closed. The neighbors whispered about him, but no one ever dared to ask questions. They said he was a former government worker, that he had seen too much and lost his mind. Others claimed he was hiding something far worse. One autumn evening, a young journalist named Clara decided to investigate. She had heard the rumors, and the more she listened, the more she felt drawn to the mystery. The house sat on the edge of a dense forest, surrounded by thick hedges that seemed to grow wilder each year. The door was rusted shut, and the front yard was overgrown with weeds and dead leaves. It looked like it had been abandoned for decades. Clara knocked. No answer. She tried again, louder this time. Still nothing. Frustrated, she climbed over the fence and walked up the creaking steps. The door gave way with a groan, revealing a dark hallway lined with peeling wallpaper. A single flickering bulb cast long shadows across the floor. The air inside smelled of mildew and old paper. She wandered through the house, finding a study filled with stacks of files, books, and yellowed newspapers. One book caught her eye: *The Lost Files of Project X-9*. She opened it, and the pages were filled with strange diagrams, maps, and notes written in a hurried, almost frantic hand. The text spoke of secret experiments, classified projects, and people who had disappeared without a trace. There were references to a "hidden facility" deep in the woods, and a list of names that didn’t match any known records. As she read, the temperature in the room dropped. The lights flickered, and a low hum filled the air. Clara felt a chill run down her spine. She closed the book and stepped back, only to find the door now locked from the inside. Her heart pounded as she turned around, scanning the room for an exit. The windows were all sealed, and the walls seemed to close in. Suddenly, the lights went out. In the darkness, she heard a soft tapping, like someone knocking on the wall. Then, a voice—low, calm, and distant. "You shouldn't have come here." Clara froze. She couldn't tell if it was real or just her imagination. The tapping grew louder, more insistent. Then, silence. When the lights came back on, the room was exactly as she had left it, except for one thing: the book had moved slightly, as if someone had just placed it there. She ran out of the house, breathless, and stumbled into the cold night air. The forest loomed behind her, its trees swaying as if whispering secrets. She didn't look back. Days passed, and Clara tried to forget what she had seen. But the images haunted her—the strange documents, the locked door, the voice. She began to research the town's history, digging through archives and old records. What she found was even more unsettling. The town had once been a hub for military testing, and several buildings had been destroyed under mysterious circumstances. There were reports of missing persons, unexplained disappearances, and a series of accidents that were never properly investigated. Most disturbing of all was a file she found buried in the local records: a report from 1972 detailing a secret experiment called "Project Echo." It described a method of communication using sound waves, capable of influencing human thought and behavior. The project was supposedly shut down, but the final entry in the report was incomplete, ending with a single line: "Subject 453 is still active." Clara returned to the house one last time, determined to uncover the truth. This time, the door was open. Inside, the air was thick with dust and silence. She found a basement door at the end of the hallway, which had been sealed with a heavy metal lock. She pried it open with a crowbar, revealing a narrow staircase leading downward. At the bottom, she found a small room lined with wires, old computers, and a large circular device that resembled a sound amplifier. In the center stood a chair, covered in dust. On the wall was a faded sign: "Test Subject 453." As she stepped closer, the air vibrated with a low, resonant tone. The walls seemed to pulse, and the temperature dropped again. She heard the same voice, clearer this time. "You are not the first. You will not be the last." Clara backed away, heart racing. As she climbed back up, the house seemed to shift around her, the walls stretching and twisting. When she finally emerged into the night, the forest was gone. In its place was an empty field, and the house was nowhere to be seen. She never told anyone what she had found. But every now and then, in the quiet hours of the night, she would hear the same low hum, and wonder if the project was still active, waiting for the next subject to arrive.