Carthoris drew a small key from his leathern pocket-pouch.
"Look at this," he said, handing it to the man. "If you know aught of locks, you will know that the mechanism which this unlooses is beyond the cunning of a picker of locks. It guards the vitals of the instrument from crafty tampering. Without it an enemy must half wreck the device to reach its heart, leaving his handiwork apparent to the most casual observer."
The servant took the key, glanced at it shrewdly, and then as he made to return it to Carthoris dropped it upon the marble flagging. Turning to look for it he planted the sole of his sandal full upon the glittering object. For an instant he bore all his weight upon the foot that covered the key, then he stepped back and with an exclamation as of pleasure that he had found it, stooped, recovered it, and returned it to the Heliumite. Then he dropped back to his station behind the nobles and was forgotten.
A moment later Carthoris had made his adieux to Thuvan Dihn and his nobles, and with lights twinkling had risen into the star-shot void of the Martian night.
