Above them on the stairs was descending another slave, innocent of what had transpired below, and the two men bowled it over in their haste to get past. All the way to the bottom of the stairs it tumbled; and that delayed pursuit for the moment needed by the Earth-men to gain the upper corridor. Quickly they darted through the door; there was no way they could lock or block it, so they had to run on. Taking to the left, they found themselves in the little entrance room, and from there their only course led up the corridor leading to Xantra's quarters and the control alcove. Arrived there, the two men found the door ajar, but they paused irresolute before it, hardly daring to go in. They had no choice, however, for behind, only fifteen feet away, came the van of the animal-men. They pushed through the door, closed and bolted it, then, wheeling tigerishly, surveyed the room. * * * * * They saw no one. They were not relieved at this. Xantra might well be there; he, as well as Vivian, would be invisible to them. And he had every opportunity of striking first; even then he might be preparing to deal with them, if he was in the room. The slaves were not attempting to break in the door to get them--and this was ominous: it argued that the master was there. The two men stood motionless at the door, peering intently at the rug in search of telltale footprints. Then Clee touched Jim's shoulder and whispered faintly in his ear: "Cloves! Smell it?" Jim nodded. Slowly, on guard every second, they advanced to the alcove. They saw no sign of anyone there, though the odor of cloves was stronger. Jim grabbed a chair and held it ready, and Clee followed suit with a small, heavy tabouret. Cautiously, methodically, the two men began to reconnoitre the large room, examining foot by foot the rug in search of the faint clear prints that would reveal the presence of their enemy. The smell of cloves was beginning to dull their brains a little. Clee saw the danger in this, and whispered to Jim: "Faster! Xantra may be insidiously anaesthetizing us! We've got to find where he is--quick!" They hastened their search, feeling more and more sure that Xantra was close by. And not till then did Clee remember that he had a way to discover Xantra's location. Jim heard him curse under his breath; saw him put down the tabouret and take out his tobacco; and knew at once what he was about to do. He went close to Clee, to guard him with his chair against possible attack. * * * * *