Then the desire to push further and further into the unknown again came with an overwhelming insistency and he turned his face eastward where the grass was greener and low clouds hung like garlands of red and gold upon the horizon. The stream of birds from the rookery was flying in the same direction. Soon he discovered its goal--a marsh of considerable extent which was the feeding-ground. Numbers of the long-legged egrets were wading in the shallow water, stopping now and then to dart their long, sharp bills into the throngs of fish dashing about their feet. Others stood motionless on the margin, like statuettes hewn out of purest marble; though seemingly dozing, they were very much on the alert as Warruk discovered when he tried to stalk one of them. He could never approach closer than a dozen good paces before the bird flapped away to the other side of the marsh, so after repeated trials he gave up the attempt and continued his journey. The country beyond the marsh grew constantly greener and of a more cheerful character and the air of mystery surrounding the unknown deepened as he ventured further from the oasis. But life was not so abundant and the animals living under conditions varying little from the normal were more wary. So, after a few days of wandering and exploration Warruk returned to the spot so densely populated by the creatures that had fled before the drought. They were there still; in fact, many newcomers had been added to their number. As before, they moved noiselessly in the deep shadows and drank of the black water in the silent pools. But something about the place had changed. It differed in some respect from the haven of a few days before. Warruk sensed the change but at first could not discover what it was further than to note an offensive odor that penetrated into even the most hidden recesses. He sniffed the air in all directions; the stench came from overhead. It was then he noted that the white birds that had made the treetops their home were no more. Also the lines of twinkling wings linking the nesting site with the marsh in which they fed were lacking. The place seemed strangely deserted and unnatural without their hoarse croaks and flashing bodies among the green leaves. However, newcomers to the locality had taken their place. Huge, black birds circled over the forest island. Gaunt, dusky forms sat ghoul-like on the stick platforms that had been nests filled with impatient, squealing young birds, or flapped heavily and clumsily through the branches. The oasis, now reeking of desolation far more than did the upper country when Tumwah descended upon it, had been deprived of its attractiveness and Warruk lost no time in leaving it. He followed the little watercourse straight to the marsh. And there new experiences awaited him.