The plane slowed and leveled out about a mile aboveground. Up ahead, the Viennese castle glowed like a fairy tale palace. When the pilot gave the thumbs-up, Gerald Blanchard looked down, checked his parachute straps, and jumped into the darkness. He plummeted for a second, then pulled his cord, slowing to a nice descent toward the tiled roof. It was early June 1998, and the evening wind was warm. If it kept cooperating, Blanchard would touch down directly above the room that held the Koechert Diamond Pearl. He steered his parachute toward his target.