He had not been mistaken; they were going faster, faster even than their efforts with the poles would account for. With the narrowing of the bed of the stream, the current was taking on a new swiftness. Shann said as much and Thorvald nodded. "We're approaching the first of the rapids." "Where we get off and walk around," Shann croaked wearily. The dust gritted between his teeth, irritated his eyes. "Do we stay beside the river?" "As long as we can," Thorvald replied somberly. "We have no way of transporting water." Yes, a man could live on very slim rations of food, continue to beat his way over a bad trail if he had the concentrate tablets they carried. But there was no going without water, and in this heat such an effort would finish them quickly. Always they both listened for another cry from behind, a cry to tell them just how near the Throg hunting party had come. "No Throg flyers yet," Shann observed. He had expected one of those black plates to come cruising the moment the hound had pointed the direction for their pursuers. "Not in a storm such as this." Thorvald, without releasing his hold on the raft pole, pointed with his chin to the swirling haze cloaking the air above the cut walls. Here the river dug yet deeper into the beginning of a canyon. They could breathe better. The dust still sifted down but not as thickly as a half hour earlier. Though over their heads the sky was now a grayish lid, shutting out the sun, bringing a portion of coolness to the travelers. The Survey officer glanced from side to side, watching the banks as if hunting for some special mark or sign. At last he used his pole as a pointer to indicate a rough pile of boulders ahead. Some former landslide had quarter dammed the river at that point, and the drift of seasonal floods was caught in and among the rocky pile to form a prickly peninsula. "In there----" They brought the raft to shore, fighting the faster current. The wolverines, who had been subdued by the heat and the dust, flung themselves to the rocks with the eagerness of passengers deserting a sinking ship for certain rescue. Thorvald settled the map case more securely between his arm and side before he took the same leap. When they were all ashore he prodded the raft out into the stream again, pushing the platform along until it was sucked by the current past the line of boulders. "Listen!" But Shann had already caught that distant rumble of sound. It was steady, beating like some giant drum. Certainly it did not herald a Throg ship in flight and it came from ahead, not from their back trail. "Rapids ... perhaps even the falls," Thorvald interpreted that faint thunder. "Now, let's see what kind of a road we can find here."