The engineer leaped in and dragged the drowning man to safety, after a desperate struggle with the torrent. But in the wild swirl, both the food-pack and the rod went adrift. The moment he had rescued his companion, Blake rushed away downstream, leaping like a goat from rock to rock. He at last overtook the rod, caught in the eddy of a pool. Of the pack he could find no trace. He returned to Ashton and silently handed him the rod. There was no need for him to admonish. The loss of all the food and the narrowness of his escape had sobered the younger man. He resumed his work with a cautious swiftness of movement that avoided all needless risks yet never hesitated to encounter and rush through the dangers that could not be avoided. In this he copied Blake. All the time they were advancing down the angry torrent, deeper and deeper into its secret stronghold,--creeping, crawling, leaping, wading, swimming--step by step, turn after turn, wresting from the abyss that which the engineer was resolved to learn, even though he should learn, only to perish. The day advanced. Steadfastly they struggled on down the bed of the river, twisting and crossing over with the winding course of the chasm; now between beetling precipices that shut out all sight of the blue-black sky; now in more open stretches where the Titanic walls swung apart and the glorious hot sun rays pierced down into the very depths to warm their drenched bodies and lighten their heavy spirits. Ashton had long since lost all count of time. His watch had been smashed in his first fall of the day. But Blake seemed to have an intuitive sense of time. At fairly regular intervals he fired a shot to tell the watchers above the extent of their progress. Sometimes the answering flag-signal could be seen waving from the rim of the canyon. But in many places those above could not come near the brink to look over. The approach of midday found the bruised and weary fighters struggling through one of the narrowest reaches of the canyon. The precipices jutted out so far that the lower depths seemed more cavern than chasm, and the river swirled deep and swift between sheer, narrow walls. Twice Ashton was swept past what should have been the next turning-point, and Blake, unable to see the figures on the rod, had to guess at his readings. At last the precipices swung apart and showed the sky at a twist in the canyon's course that was the sharpest of all the turns the explorers had as yet encountered. As Blake came wading down past Ashton, along the inner curve of the bend, he stopped and pointed skywards. Ashton raised his drooping head and peered up at the rim of the opposite wall. From the brink a dense column of green-wood smoke was rising into the indigo sky. "One more set-up," shouted Blake.