Morey dived. Almost simultaneously the Thessians succeeded in the maneuver they had been attempting for some time. There were a dozen rays flaring wildly from the ship, searching blindly over the sky and ground, hoping to stumble on the enemy ship, while their own ship dived and twisted. Arcot was busily dodging the sweeping rays, but finally one hit his viewplates, and his own ship was blind. Instantly he threw the ray screen out, cutting off his own molecular ray. His own cosmics he set rotating in cones that covered the three dimensions--save below, where the city lay. Immediately the Thessian had retreated to this one segment where Arcot did not dare throw his own rays. The Thessian cosmics continued to make his relux screens necessary, and his ship remained blind. His ray screen was showing signs of weakening. The Thessians got a third ray into position for operation, and opened up. Almost at once the tubes heated terrifically. In an instant they would give way. Arcot threw his ship into space, and let the tubes cool under the water jacket. Morey reported the coils ready as soon as he came out of space. Arcot cut in the new set of eyes, and put up his molecular ray screen again. Then he cut the energy back to the coils. Half a mile below the enemy ship was vainly scurrying around an empty sky. Wade laughed at the strange resemblance to a puppy chasing its tail. The _Ancient Mariner_ was utterly lost to them. "Well, here goes the last trick," said Arcot grimly. "If this doesn't work, they'll probably win, for their tubes are better than ours, and they can maneuver faster. By win I mean force us to let them attack Ortol. They can't really attack us; artificial space is a perfect defense." Arcot's molecular ray apprized the Thessians of his presence. Their screen flared up once more. Arcot was driving straight toward their ship as they turned. He snapped the relux screens in front of his eyes an instant before the enemy cosmics reached his ship. Immediately the thud of four heavy relays rang through the ship. The quarter of a million ton ship leaped forward under a terrific acceleration, and then, as the four relays cut out again, the acceleration was gone. The screen regained life as Arcot opened the shutters. Before them, still directly in their path, was the huge Thessian ship. But now its screen was down, the relux iridescent in decomposition. It was falling, helplessly falling to the rocky plateau seven miles below. Its rays reached out even yet--and again the _Ancient Mariner_ staggered under the terrific pull of some acceleration. The Thessian ship lurched upward, and a terrific concussion came, and the entire neighborhood of that projector disappeared in a flash of radiation.