The plane slowed and leveled out about a mile above ground. 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. A couple of days earlier, Blanchard had appeared to be just another twentysomething on vacation with his wife and her wealthy father. The three of them were taking a six-month grand European tour: London, Rome, Barcelona, the French Riviera, Vienna. When they stopped at the Schloss Schönbrunn, the Austrian equivalent of Versailles, his father-in-law’s VIP status granted them a special preview peek at a highly prized piece from a private collection. And there it was: In a cavernous room, in an alarmed case, behind bulletproof glass, on a weight-sensitive pedestal — a delicate but dazzling 10-pointed star of diamonds fanned around one monstrous pearl. Five seconds after laying eyes on it, Blanchard knew he would try to take it.