He ran the simulation forward over a couple of decades, then back, then forward again. Saskia sensed he must have his finger on a scroll bar in some UI, racking it up and down across the years. This made obvious something that might have gone unnoticed if they’d watched it more slowly, which was that the neighborhood was moving vertically upward—actually gaining altitude, here and there, in fits and starts. More precisely, the level of the ground itself stayed the same but the houses were rising into the air, new foundations being slipped under them. "We see the rise of the house-jacking industry," T.R. remarked. "Here are its fruits."