The flickering light revealed the four boats drifting in brackish, barely moving water, close to one another and swinging this way and that. The river had broadened, overflowing its banks. The covering tangle pressed low, barely above their heads. A short distance farther on it merged into the water, blocking the way.
“The bushes have choked the stream,” Octrago announced. “We shall have to clear it. Stay in the boats for the time being—there might be water lizards about.”
At his bidding they paddled the canoes up against the damming tangle and began hacking with swords and axes. Vorduthe tried not to think about how far the blockage might extend, but shortly it became clear that the bed of the stream was logged with flotsam and completely silted up. They were able to step out of the boats and continue the work while standing on the spongy matting.
At first they thought to cut a path through the bush and drag the canoes over the detritus, to what they hoped was clear water beyond. In the event it proved easier to dig out a narrow channel through which to half-float, half-haul the boats, crawling meanwhile beneath the thorny mass overhead. They labored in darkness, relieved intermittently by the light of a firebrand; until at last there was a sudden rush of water as the final bar of silt was shucked away and the channel made contact with the continuing riverbed.
The water level here, fed only by what had seeped through the blockage, was lower than on the other side, but now it began to rise and the current to quicken. Pausing only to splash some of the mud off themselves, the Arelians clambered back into their boats to follow the current once more.
To Vorduthe’s surprise the prow of his boat suddenly dipped sharply. He heard the scrape of Octrago’s flint. Sputtering flames gave sight of new surroundings.
The vegetation was gone. They floated now through a tunnel whose walls were of bare rock. The stream had probably entered a hillside, Vorduthe thought. But at the same time the boats were quickening their pace; they were on a downward slope, descending deep underground.
The river swirled and boiled as it swept through the winding cave. In places the roof was so low that the boats barely scraped through and the passengers were obliged to press themselves below the rough-carved rims of the timber-like pods.
They made their way by the poor light of the briefly burning brands. If the torches happened to die together there was total darkness for a while and the boats bumped against the rough walls of the tunnel and even into one another, but generally it was not too difficult to hold them steady. Soon the stream leveled somewhat. The path which the river had over the ages carved out of solid rock became less irregular, so that Octrago deemed that brands should be lit only now and then. For a lengthy period they proceeded in this fashion, learning by feel how to keep the prows turned forward and how to prod themselves free of the walls on either side.
Suddenly the natural channel opened into a large cavern, its limits indistinct in the light of the torches. The river splayed out into a broad body of water which moved silently but fairly fast in the subterranean darkness, like a wide river approaching a weir.
Octrago shouted to turn the boats to the left and paddle close to the near overhang. Presently a kind of shore came in sight: a big stone ledge rising out of the waterline.
“Beach here,” Octrago called.
Stepping deftly from the leading pod as it careened on the rock, he stood holding aloft a blazing brand, facing the, others as their sandals trod the damp stone. His words echoed dully as he spoke.
“I have called a short halt here to explain that a tricky pass lies ahead,” he told them. “At the far end of this cavern the water divides in two. One part, the greater, falls into a deep fissure and after that its course is unknown to any man—perhaps it plunges endlessly into the depths of the world. The other, the one we must take, leads to our goal.”
He paused to transfer fire to a fresh brand before continuing, tossing the expired one into the water where it hissed briefly. “The current will do its best to carry us into the fissure so we must paddle with a will to find the exit. It is essential to keep as close as possible to the left-hand wall. If you lose sight of it then you will know you are being swept toward the chasm and from then on nothing can save you.
“Also, do not lag. I will locate the mouth of the exit and guide you to it, but I shall not be able to linger. If you are not in sight of the boat ahead of you then you will be lost.”
There was shifting of feet. “How near is the exit to this fissure?” someone asked.
“Very near—that is the difficulty. You must approach the tunnel mouth with all speed and resist the current for all you are worth.”
“It might be easier if the boats were roped together. We could help one another,” someone else suggested.