He trussed up the dik-dik, tying all four of its legs together securely, then he stepped back and looked up. He could see Boris's face peering down at him.
"Haul it up!" he shouted, and gave three yanks on the rope as the agreed signal. The trackers were hidden from his view, but the slack in the rope was taken up and then the dik-dik lifted clear of the island and rose jerkily up the wall of the chasm. Nicholas watched it anxiously. There was a moment when the rope seemed to snag when the carcass was two-thirds of the way to the top, but then it freed itself and snaked on up the cliff. Eventually the dik-dik disappeared from his sight, and there was a long delay until the rope end dropped back over the tip. Boris had been sensible enough to weight it with a round stone the size of a man's head, and he was hanging over the top of the cliff, watching its progress and signalling to his men to control the descent.
When the end of the weighted line touched the surface of the water it was just out of Nicholas's reach. From the top of the cliff Boris began to swing the line until the end of it pendulumed close enough for Nicholas to grab it. With a bowline knot Nicholas tied a loop in the end of the line and slipped it under his armpits. Then he looked up at Boris.
"Heave away!" he yelled, and tugged the dangling rope three times. The slack tightened and then he was lifted off his feet. He began to ascend in a series of spiralling jerks and heaves. As he rose, the belled wall of the chasm arched in to meet him, until he could fend off from the rock with his bare feet and stop himself spiralling at the end of the rope. He was fifty feet from the top of the cliff when suddenly he stopped abruptly, dangling helplessly against the rock face.
"What's going on?" he shouted up at Boris.
"Bloody rope has jammed," Boris yelled back. "Can you see where it is stuck?"
Nicholas peered up and realized that the rope had rolled into a vertical crack in the face, probably the same one that had almost stopped the dikdik reaching the top. However, his own weight was almost five times that of the little antelope, and had forced the rope much more deeply into the crack.
He was suspended high in the air, with a drop of almost a hundred feet under him.
"Try and swing yourself loose! Boris shouted down at him. Obediently, Nicholas kicked himself back and twisted on the rope to try and roll it clear. He worked until the sweat streamed down into his eyes and the rope had rubbed him raw under the arms.
"No use," he shouted back at Boris. "Try to haul it out with brute force!
There was a pause, and then he saw the rope above the crack tighten like a bar of iron as five strong men hauled on the top end with all their strength. He could hear the trackers chanting their working chorus as they threw all their combined weight on the line.
His end of the line did not budge. It was a solid jam, and he knew then that they were not going to clear it. He looked down. The surface of the water seemed much further than a hundred feet below.
"The terminal velocity of the human body is one hundred and fifty miles an hour," he reminded himself. At that speed the water would be like concrete.
"I won't be going that fast when I hit, will I? he tried to reassure himself. He looked up again. The men on the top of the cliff were still hauling with all their weight and strength. At that moment one of the strands of the nylon rope sheared against the cutting edge of the rock crack, and began to uncurl like a long green worm.
"Stop pulling!" Nicholas screamed. "Vast heaving!" But Boris was no longer in sight. He was helping his trackers, adding his weight to the pull. The second strand of the rope parted and unravelled.
There was only a single strand holding him now.
It was going to go at any moment, he realized. "Boris, you ham-fisted bastard, stop pulling!" But his voice never reached the Russian, and with a pop like a champagne cork the third and final strand of the rope parted. He plunged downwards, with the loose end of the severed rope fluttering above his head. Flinging both arms straight upwards over his head to stabilize his flight, he straightened his legs, arrowing his body to hit feet first.
He thought about the island under him. Would he miss its red rock fangs or would he smash into it and shatter every bone in his lower body? He dared not look down to judge it in case he destabilized - his fall and tumbled in midair. If he hit the water flat it would crush his ribs or snap his spine.
His guts seemed to be forced into his throat by the speed of his fall, and he drew one last breath as he hit the surface feet first. The force of it was stunning. It was transmitted up his spine into the back of his skull, so that his teeth cracked against each other and bright lights starred his vision. The river swallowed him under. He went down deep, but he was still moving so fast when he hit the rocky bottom that his legs were jarred to the hips. He felt his knees buckle under the strain, and he thought that both his legs had been broken.
The impact drove the air out of his lungs, and it was only when he kicked off the bottom, desperate for air, that -he realized with a rush of relief that both his legs were still intact. He broke out through the surface, wheezing an coughing, and realized that he must have missed the island by only the length of his body. However, by now the current had carried him well clear of it.
He trod water on the racing stream, shook the water from his eyes and looked around him swiftly. The walls of the chasm were streaming past him, and he estimated his speed at around ten knots - fast enough to break bone if he hit a rock. As he thought it, another small island flashed past him almost close enough to touch. He rolled on to his back and thrust both feet out ahead of him, ready to fend off should he be thrown on to another outcrop.
"You are in for the whole ride, he told himself grimly.
"There is only one way out, and that is to ride it to the bottom." He was trying to calculate how far he was above the point where the river debauched from the chasm through the pink stone archway, how far he still had to swim.
"Three or four miles, at the least, and the river falls almost a thousand feet. There are bound to be rapids and probably waterfalls ahead," he decided.
"From here it does not look good. I' say the betting is three to one against getting through without leaving some skin and meat on the rocks behind you."
He looked up. The walls canted in from each side, so that at places they almost met directly over his head. There was only a narrow strip of blue sky showing, and the depths were gloomy and dank. Over the ages the river had scoured the rock as it cut its way through.
"Damned lucky this is the dry season. What is it like down in here in the rainy season?" he wondered. He looked up at the high-water mark etched on the rock fifteen or twenty feet above his head.
Shuddering at the image he looked down again, concentrating on the river ahead. He had his breath back by now, and he checked his body for any damage. With relief he decided that, apart from some bruising and what felt like a sprained knee, he was unhurt. All his limbs were responding, and when he swam a few strokes to one side to avoid another spur of rock, even the sore knee worked well enough to get him out of trouble. Gradually he became aware of a new sound in the canyon. It was a dull roar, growing stronger as he sped onward down The walls of the chasm converged upon each other, the gut of rock narrowed and the flood seemed to accelerate as it was squeezed in and confined. The sound of water built up rapidly into a thunder that reverberated in the canyon. Nicholas rolled over and swam with all his strength across the current until he reached the nearest rock wall.
He tried to find a handhold, a place where he could anchor himself, but the rock was polished smooth by the river. It slipped past under his desperately grasping hands, and the river bellowed in his head. He saw the surface around him flatten out and smooth like solid glass. Like a horse laying back its ears as it gathers itself for a jump, the river had sensed what lay ahead.
Nicholas pushed himself away from the rock wall to try and give himself room in which to manoeuvre, and pointed his feet once more down river. Abruptly the air opened under him and he was launched out into space. All around him white spurning water filled the air, and he was swirled off balance and tossed like a leaf in the torrent The drop seemed to last for ever, and his stomach swooped against his ribs. Then once more he struck with all his weight and was driven far below the surface. He fought his way up and abruptly burst out through the surface with his breathing whistling up his throat.
Through streaming eyes he saw that he was caught up in the bowl of swirling water below the falls. The waters revolved and eddied, turning in a stately minuet upon themselves.
As he turned, he saw first the high sheet of white water of the falls down which he had tumbled, and then still turning, the narrow exit from the basin through which the river resumed its mad career downstream. But for the moment he was safe and quiet here in the back-eddy below the falls. The current pushed him against the side of the basin, close in beneath the chute of the falls. He reached out and found a handhold on a clump of mossy fern growing out of a crack in the wall.
Here, at last, he had a chance to rest and consider his position. It did not take him long, however, to realize that his only way out of the chasm was to follow the course of the river and to take his chances with whatever lay downstream. He could expect rapids, if not another set of falls like this one that thundered away close beside him.
If only there were some way up the wall! He looked up, but his spirits quailed as he considered the overhang that formed a cathedral roof high above him.
While he still stared upwards, something caught his eye. Something too regular and regimented to be natural.
There was a double row of dark marks running vertically up the wall of rock, beginning at the surface of the water and climbing up the wall to the rim almost two hundred feet overhead. He relinquished his hold on the clump of fern and dog-paddled slowly down to where these marks reached the water.
As he reached them he realized that they were niches, cut about four inches square into the wall. The two rows were twice the spread of his arms apart, and the niche in one row lined up in the horizontal plane exactly with its neighbour in the second row.
Thrusting his hand into the nearest opening, he found that it was deep enough to accommodate his arm to the elbow. This opening, being below the flood level of the waters, was smoothed and worn, but when he looked to those higher up the wall, above the water mark, he saw that they had retained their shape much more clearly. The edges were sharp and square.
"My word, how old are they to have been worn like that?" he marvelled.
"And how the hell did anybody get down here to cut them?" He hung on to the niche nearest him and studied the pattern in the cliff face. "Why would anybody go to all that amount of trouble?" He could think of no reason nor purpose. "Who did this work? What would they want down here?" It was an intriguing mystery.
Then suddenly something else caught his eye. It was a circular indentation in the rock, precisely between the two rows of niches and above the highwater mark. From so far below it looked to be perfectly round - another shape that was not natural.
He paddled further around, trying to reach a position from which he would have a clearer view of it. It seemed to be some sort of rock engraving, a plaque that reminded him strongly of those marks in the black boulders that flank the Nile below the first cataract at Aswan, placed there in antiquity to measure the flood levels of the river waters. But the light was too poor and the angle too acute for him to be certain that it was manmade, let alone to recognize or read any script or lettering that might have been incorporated in the design.
Hoping to devise some way of climbing closer, he tried to use the stone niches as aids. With a great deal of effort, usin them as foot-and handholds, he managed to lift himself out of the water. But the distances between holds were too great and he fell back with a splash, swallowing more water.
"Take it easy, my lad - you still have to swim out of here. No profit in exhausting yourself. You will just have to come back another day to get a closer look at whatever it is up there."
Only then did he realize how close he was to total exhaustion. This water coming down from the Choke mountains was still cold with the memories of the high snows. He was shivering until his teeth chattered.
"Not far from hypothermia. Have to get out of here now, while you still have the strength."
Reluctantly he pushed himself away from the wall of rock and paddled towards the narrow opening through which the Dandera river resumed the headlong rush to join her mother Nile. He felt the current pick him up and bear him forward, and he stopped swimming and let it take him.
"The Devil's roller-coaster!" he told himself. "Down and down she goes, and where she stops nobody knows."
The first set of rapids battered him. They seemed endless, but at last he was spewed out into the run of slower water below them. He floated on his back, taking full advantage of this respite, and looked upwards. There was very little light showing above him, for the rock almost met overhead. The air was dank and dark and stank of bats. However, there was little time to examine his surroundings, for once again the river began to roar ahead of him. He braced himself rilentally for the assault of turbulent waters, and went cascading down the next steep slide.
After a while he lost track of how far he had been carried, and how many cataracts he had survived. It was a constant battle against the cold and the pain of sodden lungs and strained muscle and overtaxed sinew. The river mauled him.
Suddenly the light changed. After the gloom at the bottom of the high cliffs it was as though a searchlight had been shone directly into his eyes, and he felt the force and ferocity of the river abating. He squinted up into bright sunlight, and then looked back and saw that he had passed out below the archway of pink rock into that familiar part of the river which he had explored with Royan. Coming up ahead of him was the rope suspension bridge, and he had just sufficient strength remaining to paddle feebly towards the small beach of white sand below it.