While sketching the Brooklyn Bridge during a public meeting dedicated to the completion of its Manhattan tower, Leopold notices Stuart Besser taking photographs with an anachronistically small camera. Stuart is an amateur physicist (and great‑great‑grandson of Leopold) from 21st‑century New York who has discovered the existence of gravitational time portals. Later, Leopold catches Stuart in the Duke's study, photographing his schematic diagrams. When Stuart attempts to flee, Leopold follows and tries to save him from falling off the unfinished bridge, only to fall with him into the time portal.