        Although he couldn’t be sure that they hadn’t been on the island the day before, they weren’t on the beach, and their manner of departure implied that they could just beam themselves back and forth.  He made a special note that there was no shimmering translucence as they vanished—unlike Star Trek’s transporters—they were just there one moment and gone the next.  Furthermore, their departure had caused the sand to blow around, as if the atmosphere was rushing back into the space where they had been.  