The sanctuary was empty except for a handful of visitors listening to a young man giving the day's last tour. He was leading them in a single-file line along a well-known route on the floor-an invisible pathway linking six key architectural points within the sanctuary. Generations of visitors had walked these straight lines, connecting the points, and their countless footsteps had engraved an enormous symbol on the floor.
The Star of David, Langdon thought. No coincidence there. Also known as Solomon's Seal, this hexagram had once been the secret symbol of the stargazing priests and was later adopted by the Israelite kings-David and Solomon.