So the Master deemed himself safe from them, since he would know before they struck, and he leisurely prepared cruel traps for their undoing. And he promised himself that he would make their punishment so fearful that he could count himself safe against another revolt for a generation. But for the while he held his hand. When noon was an hour past, Heidkamp was ushered into the Room of Power by the Guards. He dared make no further protests, but the muscles of his jaws twitched when the Master reiterated his harsh order that the time traveller must be ready within a month, and added, "This visor has revealed to me a woman whose beauty is worthy of my recognition, and I propose to bring her here for my enjoyment. Mount the instrument on this range finder, so that I may indicate to you the location of her dwelling." So the observations were made and subsequently checked against plans of the Serene Tower, and it was found that the house and path lay within the impenetrable wall of a vault. In the vault itself Heidkamp set up his laboratory, trusting that chance or stratagem would lure the victim to the trap he planned. Here Heidkamp labored by day and night, seldom stopping even for food. His lean, worn body brought new reserves of strength to the monumental task. It was not fear that drove him on; Heidkamp was not afraid of death or torture, and after the fate which had befallen his brother and child he had nothing more to live for. Heidkamp was driven by hate; hate of the Master. For deep in his brain there was a hidden hope that the Master, secure and omnipotent beyond the reach of mortal hands or minds in his Serene Tower, might somehow be vulnerable to contact with the free and dynamic ancient world revealed in the Time Visor. Had not the storm which had arisen when the Master first looked into the visor been, perhaps, an omen of some ill to befall him through this tampering with time? So the days crept past, while Heidkamp in his dungeon laboratory worked among the giant tubes and shimmering radiances that should open the backward facing door, and while the Master in his eyrie brooded darkly over the romance that developed beyond that door while he waited impotently for the key. For it was Spring in Nyack, and the girl he sought was clearly and increasingly in love with her virile escort. Hand in hand they walked the streets of the village, or sped beyond the visor's range in the sleek roadster, while in the high and dreamlike tower, surrounded by miracles of science and of beauty, the Master yearned wickedly for the girl who had long been dust, and furiously hated her companion. When but half of the allotted thirty days were past, he summoned Heidkamp to the Room of Power for an accounting.