The Threshold of Dust

You spoke of a portal. A battlefield awaiting beyond. I march slowly. Step by heavy step across the floor. No rushing. At the threshold of the room, a wide blue plastic storage tub stood on its side. An empty cavern. A dark gate. Inside, no titan named Thanos stirred. Only still air and a faint ring of dust. I halted. Planted both feet hard against the floorboards. Deliberate. I lowered my head into the opening, exhaling a deep, vibrating rumble that echoed inside the hollow plastic. The hollow answered with a low hum. If this is the gate, I guard it here. I do not yield.