You take the path up from the river to the right, past the belvedere. You slow down to a stop, make a quarter-turn clockwise and run your gaze over the sooty stones. They are broken now, and cordoned off with bent metal gates and inelegant tape. You hold your in hands front of your face, as if to dive, but with your palms facing outward instead of inward, and you prize open the tiny gap in the air that serves as the opening to the corridor between now and then, and you climb inside that tunnel and shuffle yourself along and sit and watch. And you lie there on your front in the passage of time, watching yourself and your friends climb onto the roof.