As the robot picked their way through a narrow passage between two rock faces the tower came into view; it was very close now, not more than another hour’s walk. As they carefully chose their footing, the robot spotted something glinting among the rocks and stopped to pick it up. A flat, square object with a delicate metal aperture along one side bearing the marking “2HD.” With a piece of string from their pack, the robot attached the object to their walking staff; an enigmatic ornament for a journey full of mystery.