Flesh and blood have their limits as far as speed is concerned, but Lackland came very close to setting new ones. He did not stop to solve any differential equations which would tell him the rock’s time of arrival; he threw power into the motors, turned the tank ninety degrees in a distance that threatened to twist off one of its treads, and got out from the mouth of the channel which was guiding the huge projectile toward him. Only then did he really come to appreciate the architecture of the city. The channels did not come straight into the open space, as he had noticed; instead, they were so arranged that at least two could guide a rock across any portion of the plaza. His action was sufficient to dodge the first, but it had been forseen; and more rocks were already on their way. For a moment he looked around in all directions, in a futile search for a position which was not about to be traversed by one of the terrible projectiles; then he deliberately swung the nose of the tank into one of the channels and started uphill. There was a boulder descending this one too; a boulder which to Barlennan seemed the biggest of the lot — and to be growing bigger each second. The Mesklinite gathered himself for a leap, wondering if the Flyer had lost his senses; then a roar that outdid anything his own vocal apparatus could produce sounded beside him. If his nervous system had reacted like that of most Earthly animals he would have landed halfway up the hill. The startled reaction of his race, however, was to freeze motionless, so for the next few seconds it would have taken heavy machinery to get him off the tank roof. Four hundred yards away, fifty yards ahead of the plunging rock, a section of the channel erupted into flame and dust — the fuses on Lackland’s shells were sensitive enough to react instantly even to such grazing impact. An instant later the rock hurtled into the dust cloud, and the quick-firer roared again, this time emitting half a dozen barks that blended almost indistinguishably with each other. A fair half of the boulder emerged from the dust cloud, no longer even roughly spherical. The energy of the shells had stopped it almost completely; friction took care of the rest long before it reached the tank. It now had too many flat and concave surfaces to roll very well.

There were other boulders in position to roll down this channel, but they did not come. Apparently the giants were able to analyze a new situation with fair speed, and realized that this method was not going to destroy — the tank. Lackland had no means of knowing what else they might do, but the most obvious possibility was a direct personal attack. They could certainly, or almost certainly, get to the top of the tank as easily as Barlennan and repossess everything they had sold as well as the radio; it was hard to see how the sailors were to stop them. He put this thought to Barlennan.

„They may try that, indeed,” was the answer. „However, if they try to climb up we can strike down at them; if they jump we have our clubs, and I do not see how anyone can dodge a blow while sailing through the air.”

„But how can you hold off alone an attack from several directions at once?”

„I am not alone.” Once again came the pincer gesture that was the Mesklinite equivalent of a smile.

Lackland could see the roof of his tank only by sticking his head up into a tiny, transparent view dome, and he could not do this with the helmet of his armor on. Consequently he had not seen the results of the brief „battle” as they applied to the sailors who had accompanied him into the city.

These unfortunates had been faced with a situation as shocking as had their captain when he first found himself on the roof of the tank. They had seen objects — heavy objects actually falling on them, while they themselves were trapped in an area surrounded by vertical walls. To climb was unthinkable, though the sucker-feet which served them so well in Mesklin’s hurricanes would have served as adequately in this task; to jump as they had now seen their captain do several times was almost as bad — perhaps worse. It was not, however, physically impossible; and when minds fail, bodies are apt to take over. Every sailor but two jumped; one of the two exceptions climbed — rapidly and well — up the wall of a „house.” The other was Hars, who had first seen the danger. Perhaps his superior physical strength made him slower than the others to panic; perhaps he had more than the normal horror of height. Whatever the reason, he was still on the ground when a rock the size of a basketball and almost as perfectly round passed over the spot he was occupying. For practical purposes, it might as well be considered to have struck an equivalent volume of live rubber; the protective „shell” of the Mesklinites was of a material chemically and physically analogous to the chitin of Earthly insects, and had a toughness and elasticity commensurate with the general qualities of Mesklinite life. The rock bounded twenty-five feet into the air against three gravities, hurtling entirely over the wall which would normally have brought it to a stop, struck at an angle the wall of the channel on the other side, rebounded, and went clattering from wall to wall up the new channel until its energy was expended. By the time it had returned, in more leisurely fashion, to the open space the main action was over; Hars was the only sailor still in the plaza. The rest had brought some degree of control into their originally frantic jumps and had either already reached the top of the tank beside their captain or were rapidly getting there; even the climber had changed his method of travel to the more rapid leaping.

Hars, unbelievably tough as he was by terrestrial standards, could not take the sort of punishment he had just received completely without injury. He did not have his breath knocked out, since he lacked lungs, but he was scraped, bruised, and dazed by the impact. Fully a minute passed before he could control his motions sufficiently to make a coordinated attempt to follow the tank; why he was not attacked during that minute neither Lackland, Barlennan, nor Hars himself was ever able to explain satisfactorily. The Earthman thought that the fact that he was able to move at all after such a blow had frightened any such thoughts out of the minds of the city dwellers; Barlennan, with a more accurate idea of Mesklinite physique, thought that they were more interested in stealing than in killing and simply saw no advantage in attacking the lone sailor. Whatever the reason, Hars was permitted to regain his senses in his own time and, eventually, to regain the company of his fellows. Lackland, finally brought up to date on just what had happened, waited for him; when he finally reached the vehicle two of the crew had to descend and practically throw him to the roof, where the rest promptly undertook first-aid measures.

With all his passengers safely aboard, some of them crowded so close to the edge of the roof that their new-found indifference to height was a trifle strained, Lackland headed uphill once more. He had warned the sailors to keep clear of the gun muzzle, and kept the weapon trained ahead of him; but there was no motion on the ridge, and no more rocks fell. Apparently the natives who had launched them had retreated to the tunnels which evidently led up from their city. This, however, was no assurance that they would not come out again; and everyone on and in the tank kept a sharp lookout for any sort of motion.

The channel they were climbing was not the same as the one they had descended, and consequently did not lead directly to the sled; but the Bree became visible some distance before they reached the top, owing to the tank’s height The crew members who had been left behind were still there, all looking with evident anxiety down into the city. Dondragmer muttered something in his own language concerning the stupidity of not keeping an all-around watch, which Barlennan repeated in amplified form in English. However, the worry proved fruitless; the tank reached the stranded sled, turned, and was hitched up to its load without further interference. Lackland, once more under way, decided that the giants had overestimated the effectiveness of the gun; an attack from close quarters — emerging, for example, from the concealed tunnel mouths which must shelter the individuals who started the rocks downhill — would leave the weapon completely helpless, since neither high explosive nor thermite shells could be used close to the Bree or her crew.