I dreamed I was the last person in a factory that never closed

I was walking through the same corridors I’ve walked for twenty years—same creaking floor, same fluorescent hum—but no one else was there. The machines were still running, but empty. I kept checking my watch; it said 3:17 a.m., but the clock on the wall said 8:04 a.m. I found a coffee cup on the foreman’s desk, still warm. No one had left. Not really. And when I turned to go, the door locked behind me. I don’t know if I woke up or just stayed.