"Runners in the dark--" Dalgard frowned. "It is still sun time. What disturbs them?" To the eye Sssuri was still listening to that which his friend could not hear. "They come from afar. They are on the move to find new hunting grounds." Dalgard sat up. To each and every scout from Homeport the unusual was a warning, a signal to alert mind and body. The runners in the night--that furred monkey race of hunters who combed the moonless dark of Astra when most of the higher fauna were asleep--were very distantly related to Sssuri's species, though the gap between them was that between highly civilized man and the jungle ape. The runners were harmless and shy, but they were noted also for clinging stubbornly to one particular district generation after generation. To find such a clan on the move into new territory was to be fronted with a puzzle it might be well to investigate. "A snake-devil--" he suggested tentatively, forming a mind picture of the vicious reptilian danger which the colonists tried to kill on sight whenever and wherever encountered. His hand went to the knife at his belt. One met with weapons only that hissing hatred motivated by a brainless ferocity which did not know fear. But Sssuri did not accept that explanation. He was sitting up, facing inland where the thread of valley met the cliff wall. And seeing his absorption, Dalgard asked no distracting questions. "No, no snake-devil--" after long moments came the answer. He got to his feet, shuffling through the sand in the curious little half dance which betrayed his agitation more strongly than his thoughts had done. "The hoppers have no news," Dalgard said. Sssuri gestured impatiently with one outflung hand. "Do the hoppers wander far from their own nest mounds? Somewhere there--" he pointed to the left and north, "there is trouble, bad trouble. Tonight we shall speak with the runners and discover what it may be." Dalgard glanced about the camp with regret. But he made no protest as he reached for his bow and stripped off its protective casing. With the quiver of heavy-duty arrows slung across his shoulder he was ready to go, following Sssuri inland. The easy valley path ended less than a quarter of a mile from the sea, and they were fronted by a wall of rock with no other option than to climb. But the westering sun made plain every possible hand and foot hold on its surface.