“There is but one who may convince him, and that one be you. You must hasten at once to the court of Ptarth, and by your presence there as well as by your words assure him that his suspicions are groundless. Bear with you the authority of the Warlord of Barsoom, and of the Jeddak of Helium to offer every resource of the allied powers to assist Thuvan Dihn to recover his daughter and punish her abductors, whomsoever they may be. “Go! I know that I do not need to urge upon you the necessity for haste.” Carthoris left the council chamber, and hastened to his palace. Here slaves were busy in a moment setting things to rights for the departure of their master. Several worked about the swift flier that would bear the Prince of Helium rapidly toward Ptarth. At last all was done. But two armed slaves remained on guard. The setting sun hung low above the horizon. In a moment darkness would envelop all. One of the guardsmen, a giant of a fellow across whose right cheek there ran a thin scar from temple to mouth, approached his companion. His gaze was directed beyond and above his comrade. When he had come quite close he spoke. “What strange craft is that?” he asked. The other turned about quickly to gaze heavenward. Scarce was his back turned toward the giant than the short-sword of the latter was plunged beneath his left shoulder blade, straight through his heart. Voiceless, the soldier sank in his tracks—stone dead. Quickly the murderer dragged the corpse into the black shadows within the hangar. Then he returned to the flier. Drawing a cunningly wrought key from his pocket-pouch, he removed the cover of the right-hand dial of the controlling destination compass. For a moment he studied the construction of the mechanism beneath. Then he returned the dial to its place, set the pointer, and removed it again to note the resultant change in the position of the parts affected by the act. A smile crossed his lips. With a pair of cutters he snipped off the projection which extended through the dial from the external pointer—now the latter might be moved to any point upon the dial without affecting the mechanism below. In other words, the eastern hemisphere dial was useless. Now he turned his attention to the western dial. This he set upon a certain point. Afterward he removed the cover of this dial also, and with keen tool cut the steel finger from the under side of the pointer. As quickly as possible he replaced the second dial cover, and resumed his place on guard. To all intents and purposes the compass was as efficient as before; but, as a matter of fact, the moving of the pointers upon the dials resulted now in no corresponding shift of the mechanism beneath—and the device was set, immovably, upon a destination of the slave’s own choosing.