Kwembly ran gently aground. Beetchermarlf instantly shifted drive power to the two trucks farthest forward which had power boxes, letting the paddle-equipped ones idle, and pulled his cruiser out on the shore. “I’m out of the lake,” he reported. “Minor problem. If I travel for any distance on land with the paddles in place I’ll wear them out. If it turns out that I’m on an island, or have to go back to the water for any other reason, an awful lot of time will have been wasted taking them off and putting them on again. My first thought is to do some exploring on foot, leaving the ship right here, to get some idea of what the chances of staying ashore may be. It will take a long time, but not nearly as long as waiting for daylight. I’ll be glad of advice from you humans or orders from the captain; we’ll wait.” Dondragmer, when this was relayed to him, was prompt with his answer. “Don’t go out. Wait until the map-makers up above can decide whether you are on the same side of the river as we are, or not. As I picture the map they?ve described, there?s a good chance that the eddy carried you to the east side, which would be the right bank; we?re on the left. If they are even moderately sure of this, get back into the water and head west until they think you?re past it, no, second thought. Go until they think you?re opposite its mouth, then head south once more. I?d like to find out whether you can travel upstream with any speed at all. I know it will be slow; it may turn out that you can?t travel at all in some places along the bank.? “I’ll tell Beetch and the map people, Captain,” answered Benj. “I’ll try to get a copy of their map and keep it up to date down here; that may save some time in the future.” The directional data was not, as it happened, definitive. The location of the Kwembly could be established well enough, but the course of the river down which she had come was much less certain. The checks were many miles apart, but sufficient in number to show that the river was decidedly crooked. After some further discussion, it was decided that Beetchermarlf should get back afloat and head westward as close to shore as he could; preferably within sight of it, if the range of his lights and the slope of the lake bottom would permit it. If he could find the river mouth by sight, he was to head up it as Dondragmer had wished; if not, he was to continue along the shore until the men above were reasonably certain that he had passed the rivermouth, then turn south. It did prove possible to keep the shore within range of the Kwembly’s lights, but it took over two hours to reach the river. This had made a wide westward bend which had been missed in the checks of the cruiser’s position during the downstream drift; then it turned again and entered the lake on an eastward slant which presumably caused the counterclockwise eddy. One of the planetographers remarked that you couldn’t blame the eddy on Coriolis force because the lake was only seven degrees from the equator and on the south side, at that, of a planet which took two months to rotate. The delta, which caused the shoreline to turn north briefly, was a warning. Beetchermarlf at the helm and Takoorch at the port wing of the bridge sent the Kwembly groping around the rather irregular peninsula, slowing noticeably several times as the trucks dragged in soft bottom silt, and finally found their way into a clear channel and headed into its current. This was not swift, but the Kwembly still wasn’t afloat. The Mesklinites were in no hurry; Dondragmer gave six hours and more to the experiment of fighting the stream. They made about ten miles progress in that time. If that rate could be maintained, the cruiser would be back at the camp by a day or two after midnight, that is, in a week or so by human reckoning. It was impatience which changed the travel plans. This could not, of course, be blamed on any Mesklinite; it was Aucoin, of all people, who decided that a mile and a half an hour was not satisfactory. Dondragmer did not feel strongly about the matter; he agreed that research might as well be worked into the trip if possible. At the planner?s suggestion he sent Beetchermarlf angling westward toward what was presumably the near bank of the river. The land seemed traversable. With some misgiving he had the helmsmen remove the paddles. Removal proved much easier than installation, since the vehicle was now on dry land. Things could be laid down and life lines were not needed. Benj, on his next visit to the communication room, found the Kwembly cruising smoothly south at about ten miles an hour over flat country, interrupted by an occasional outcropping of rock and studded here and there with scrubby brush, the highest life form so far encountered on Dhrawn. The surface was firm sediment; the planetologists judged the area to be a flood plain, which seemed reasonable even to Benj. Beetchermarlf was willing to talk as usual, but it could be seen that his attention was not entirely on conversation. Both he and Takoorch were looking ahead as sharply as their eyesight and the Kwemhly’s lights would permit. There was no assurance that the going was safe; without air-scouting, the ten-mile speed was all they dared use. Anything faster would have been overrunning their lights. Whenever other duties, such as airplant maintenance, had to be performed, they stopped the cruiser and did the work together. One set of eyes, they felt, was not enough for safe travel. Every now and then, as the hours wore on, whoever was at the helm would begin to feel the treacherous assurance that there could be no danger; that they had, after all, come scores of miles now without having to change heading except to keep the river in sight. A human being would have increased the running speed bit by bit. The Mesklinite reaction was to stop and rest. Even Takoorch knew that when he was feeling tempted to act against the dictates of elementary common sense, it was time to do something about his own condition. Discovering the vehicle halted when he came to the screens on one occasion, Aucoin assumed it was a regular air-maintenance stop; but then he saw one of the Mesklinites sprawled idly on the bridge. The set had been put back in its old location, giving a view forward over the helm. Asked why the cruiser was not traveling, Takoorch simply replied that he had found himself getting casual. The administrator left in a very thoughtful mood. Eventually, this care paid off, or seemed to. For some miles the outcroppings of bed rock had been more and more frequent, though generally smaller, closer together, and more angular. The planetologists had been making guesses, futile ones with so little information, about the underlying stratigraphy. The basic surface was still hard-packed sediment, but the watchers suspected that it might be getting shallower, and that some time soon the Kwemhly might find herself on the same sort of bare rock that formed the substrate at Dondragmer’s camp. The helmsmen occasionally found it necessary now to weave slightly left or right to avoid the rock outcroppings; they even had to slow down a little from time to time. Several times in the past few hours the planetologists had rather plaintively suggested that the cruiser stop before it was too late, and pick up samples of the sediment she was running over even if the rocks were too big to collect. Aucoin simply pointed out that it would be a year or two before the sample could get up to the station anyway, and refused; the scientists retorted that a year was much better than the time which would be needed if the specimens weren?t collected. But when the Kwembly stopped, it was on Beetchermarlf’s initiative. It was a minor thing, or seemed to be; the soil ahead seemed a little darker, with a very sharp boundary between it and the surface under the cruiser. The line was not noticeable on the vision screen, but the Mesklinites spotted it simultaneously and, without words, agreed that close examination was in order. Beetchermarlf called the station to inform the human beings and his captain that he and Takoorch would be going outside for a time, and described the situation. Easy, translating the message, was promptly begged by two planetologists to persuade the Mesklinites to bring samples aboard. She assumed that even Aucoin would hardly object under the circumstances, and agreed to ask them when she called back with Dondragmer’s clearance. The captain, this time, approved the sortie, suggesting only that it be preceded by a careful look around from the bridge with the aid of the spotlights. This proved useful. A hundred yards ahead, not too far out of the range of the running lights, a small stream ran across their path and emptied into the river. Sweeping the light to starboard, this tributary could be seen arcing around parallel to the cruiser’s path from the north, then reversing its curve somewhat astern of the big vehicle and disappearing to the northwest. The Kwembly was on a peninsula some two hundred yards wide and not quite as long, bounded on the east — left — by the main river she had been following and on the other sides by the small tributary. It seemed likely to Mesklinites and human beings alike that the change in soil color which had caught the helmsmen’s attention was caused by wetting from the smaller stream, but no one was sure enough of it to cancel the proposed trip outside. Aucoin was not present. Outside, even with the aid of extra lights, the line of demarcation between the two kinds of soil was much less visible than before. Eye distance, Beetchermarlf judged, was the main cause. The crew scraped up and packaged samples of material from both sides of the line; then they went on to the stream itself. This proved to be a swift-running but shallow brook three or four body-lengths in width, its level an inch or two below the soil through which it was cutting its way. After a brief consultation, the two Mesklinites began to follow it away from the river. They had no way of telling its composition, but a bottle of its contents was secured for later testing. By the time they reached the spot where it was curving away, even the Mesklinites could see that the stream had not been in existence very long. It was eating with visible speed into its banks, washing the sediment on toward the main river. Now that they were on the outside of its curve, the undercutting of the near bank could be seen and even felt; Beetchermarlf, standing at the edge, felt it crumble suddenly away under him and found himself in the stream. It was only an inch or so deep, so he took advantage of the occasion to take another sample from its bottom before climbing out. They decided to continue upstream for another ten minutes or so, with Beetchermarlf wading and Takoorch on the bank. Before the time was up they had actually found the source of the watercourse. It was a spring, not half a mile from the Kwembly, roiling violently in the center of its basin where an underground source fed it. Beetchermarlf, investigating the middle, was knocked from his feet and carried half a body length by the upward current. There was nothing in particular to do; they had no camera equipment, no one had seriously suggested that they bring the vision set with them, and there was nothing obvious to be gained by collecting more samples. They returned to the Kwembly to give a verbal description of what they had found. Even the scientists agreed that the best step now was to get the samples back to the camp where Borndender and his fellows could do something useful with them. The helmsmen eased their cruiser into motion once more. It approached the stream and nosed through it; the mattress took up the slight dip as the trucks crossed the bottom of the widening valley, and nothing could be felt on the bridge. Not for another eight seconds. The hull was rather more than half way across the little brook when the distinction between solid and liquid began to blur. A slight lurch could be felt on the bridge; it showed on the screen far above as a tiny upward jerk of the few outside features visible. Forward motion stopped almost instantly, though the drivers kept churning. They could accomplish nothing when completely immersed in slimy mud, which the surface had so suddenly become. There was neither support nor traction. The Kwembly settled until the trucks were buried; settled until the mattress was nearly out of sight; settled almost, but not quite, to the level where she would have been literally floating in the semiliquid muck. She was stopped by two of the rock outcrops, one of which caught her under the stern just aft of the mattress, and the other on the starboard side some ten feet forward of the main lock. There was an ugly scraping sound as the cruiser’s hull canted forward and to port, and then came to rest. And this time, as Beetchermarifs sense of smell warned him only too clearly, the hull had failed somewhere. Oxygen was leaking in.