On this quest of the arrow Grom took with him only two companions--his slim, swift-footed mate, A-ya and that cunning little scout, Loob, the Hairy One. For the space of three days they journeyed due west from the Caves. Then the range of downland which they had been following swept off sharply to the south. Being bent upon exploring to the westward--though he was not very clear as to his reasons for his preference--Grom led the way down from the hills into the rankly wooded plain. For two days more they pushed on through incessant perils, the country swarming with black lions, saber-tooth, and woolly rhinoceros. As they were not fighting, but exploring, the price of safety was a vigilance so unremitting that it soon began to get on their nerves, and they were glad to take a whole day's rest in the spacious security of a banyan top, where nothing could come at them but leopards or pythons. Neither leopards nor pythons gave them any great concern. On the second day after quitting their refuge in the banyan top, they emerged from the jungle so suddenly that they nearly fell into a river, whose whitish, turbid flood ran swirling heavily before their feet. It was a mighty stream, a good half-mile in width, and at this point the current was eating away the bank so hungrily that whole ranks of tree and bush had toppled over into the tide. The great river barred their way, flowing as it did toward the north-east, and Grom reluctantly turned the course of the expedition southward, following up the shore. Swift as was the current, these folk of the Caves might have crossed it by swimming; but Grom knew that such waters were apt to swarm with giant crocodiles of varying type and unvarying ferocity, as well as with ferocious flesh-eating fish that swarmed in wolfish packs, and were able to tear an aurochs or a mastodon in pieces with their razor-edged teeth. He gazed desirously at the opposite shore, however--which looked to him much more beautiful and more interesting than that on which he stood--and wondered if he should ever be able to devise some way of reaching it other than by swimming.