“Come a little closer, hear what I have to say,” came a small voice from the ground-floor bedroom of a large home. A white-haired man pumped up by pillows lay on a single bed warmed by a multicolored blanket. “Come closer,” he whispered, “I wish to tell you something.”

As the intruder in white glanced around the room, the pictures of wolves, bears, deer, and eagles on the far wall caught her attention. But the drawing on the near wall was unlike anything she had ever seen before. It was extraordinarily beautiful and surprisingly mathematical. The visitor closed the bedroom door, and as she did, the illustration (see next page) was reflected in the full-length mirror hanging on the back of the door. In that instant, the painting’s signature became decipherable; it said, “Leonardo.”