Turning aside, they followed the empty stream bed up the hills and at last scrambled out on to the ledge from which the butterfly fountain had poured. The cave was still surrounded by lush green ferns, but it was like the eye socket in a skull, dark and empty.
‘The spring has dried up!’ Royan whispered. ‘The dam has shrivelled it. That’s the proof that the fountain was fed from Taita’s pool. Now we have diverted the river we have killed the fountain.’ Her eyes were bright and sparkling with excitement. ‘Come on. Let’s waste no more time here. Let’s get on up to Taita’s pool.’
Nicholas was the first one down into Taita’s pool. This time he had a bosun’s chair to sit in and a properly rigged block and tackle to lower him over the cliff. As he swung down around the overhang of the cliff, the chair swung awkwardly against the rock and the thumb of his right hand was trapped between the wooden seat of the chair and the wall. He exclaimed with the pain and, when he wrenched it free, he found that the skin had been torn from the knuckle and that blood was oozing up and dripping down his legs. It was painful but not serious, and he sucked the wound clean. It was still weeping drops of blood, but he had no time to attend to the injury now.
He was around the overhang, and the abyss opened under him, sombre and repellent. His eye was drawn irresistibly to the engraving on the wall, etched between the vertical rows of niches. Now that he knew what to look for, he could make out the outline of the maimed hawk. It cheered and encouraged him. Since their flight from the gorge over a month previously he had often been haunted by the feeling that they had imagined it all, that the cartouche of Taita was a hallucination, and that when they returned they would find the cliff wall smooth and unblemished. But there it was, the signpost and the promise.
He peered down past his own feet to the bottom of the gorge, and saw at once that the waterfall above the pool had been reduced to a trickle. The water still coming down the smooth black chute of polished rock was that which was filtering through the gaps and chinks in the dam wall upstream and the last drainage from the sandbanks and the pools higher up the gorge.
The level of the great pool under him had fallen drastically. He could make out the high-water level by the wet markings on the rock cliff. Fifty feet of the wall that had previously been submerged was now exposed. Another eight pairs of chiselled niches were visible in the face. Where once he had been forced to swim down to them, they were now high and dry.
However, the pool was not completely drained. It was dished below the level of the downstream outlet, so that it was unable to empty itself by gravitational flow. There was still a puddle of black water trapped in the centre, with a narrow ledge surrounding it. Nicholas landed on this ledge and stepped out of the bosun’s chair. It was strange to stand on firm rock down here where last he had struggled for his life and very nearly been sucked under and drowned.
He looked up to where beams of sunlight penetrated the upper levels of the chasm. It was like being in the bottom of a mineshaft, and he shuddered at the feel of the clammy air on his bare arms and the eerie sensation in the pit of his stomach. He tugged on the line to send the rope chair back to the surface, and then edged his way along the slippery rock ledge towards the cliff face where the rows of dark niches stood out clearly against the lighter stone.
Now he could make out the shape of the opening in the wall that had so nearly sucked him down into its dark and slimy throat. It was almost completely submerged in a deeper corner where the pool flowed back against the cliff. All that was visible above the surface was the top arch of an irregular entrance at the foot of the descending rows of niches. The rest of it was still submerged.
The ledge narrowed as he worked his way along the foot of the cliff until he had his back to the rock and was moving sideways with his toes in the water. Eventually he could go no further without actually stepping down into the water. He had no way of judging the depth of the waters, which were turbid and uninviting.
Still trying to keep his feet dry, he squatted down on the narrow ledge and leaned out so far that his balance was threatened. He steadied himself with one hand against the wall, and with the other reached out towards the partially submerged opening.
The lip of the hole was smooth, as he had remembered it, and once again it seemed to him that it was too square and straight to be anything other than man-made. As he rolled up his sleeve he noticed that his injured thumb was still bleeding, but he ignored it and thrust his arm down below the surface of the pool. He groped downwards, trying to trace the sill of the opening. He felt what seemed to be blocks of roughly dressed masonry, and reached down further until the water reached halfway up his biceps.
Suddenly some living creature, swift and weighty, swirled in the dark waters right in front of his face, and as an immediate reflex he jerked his arm out of the water. The thing followed his arm up to the surface, slashing at his bare flesh with long, needle-sharp fangs, and he had a glimpse of a head as evil and villainous as that of a barracuda. He realized instinctively that it must have been attracted by the smell of the blood from his injured thumb.
He leaped to his feet and teetered on the narrow ledge, clutching his arm. Only one of the creature’s frontal fangs had touched him, but it had opened the skin like a razor cut, a long shallow wound across the back of his right hand from which fresh blood dribbled and splattered into the pool at his feet.
Instantly the black waters seemed to come alive, roiling and seething with frenzied writhing aquatic shapes. Nicholas, his back flattened against the rock wall, stared down at them with loathing and horror. He could vaguely make out the shape of them, sinuous and ribbonlike, some of them as thick as his calf, black and gleaming.
One of them thrust its head out on to the ledge and snapped its jaws. Its eyes were huge and glistening and its snout was elongated, the long jaws lined with fangs that overlapped its thin lips. The body behind the head was six feet long, and lashed like a whip as it drove itself high up on to the ledge, reaching out for Nicholas’s bare legs. He shouted with revulsion and leaped back, stumbling and splashing on to safer footing. Clutching his bleeding hand, he stared back. The evil head had disappeared, but the surface of the pool was still agitated by the lithe ophidian shapes.
‘Eels!’ he realized. ‘Giant tropical eels.’
Of course the blood had excited them. The fall in the water-level had trapped them in the pool, congregated them in such numbers that they had probably already devoured the fish that they depended upon for food. Now they were ravenous. Probably all the pools of water that remained in the abyss were infested with these fearsome creatures. He was thankful that during his last swim in this pool he had not bled into the water.
He unwound the cotton kerchief from his neck and wrapped it round his wounded hand. The eels were a deadly threat to any attempt to explore the opening in the cliff. But already he was considering ways of ridding the pool of them and of gaining access to the underwater opening.
Slowly the frenzy in the pool quietened and its surface grew still again. Nicholas looked up to see the bosun’s chair descending, with Royan’s slim, shapely legs dangling below the wooden seat.
‘What have you found?’ she called down to him excitedly. ‘Is there a tunnel—’ then she broke off suddenly as she saw the blood on his clothing, and the bandage swathing his hand.
‘Oh dear God,’ she exclaimed. ‘What have you done? You are hurt. How badly?’ Her feet touched the ledge beside him and she slid from the chair and took his injured hand gently. ‘What have you done to yourself?’
‘It’s not as bad as it looks,’ he assured her. ‘Lots of blood but not deep.’
‘How did you do it?’ she insisted.
For an answer he tore a corner off the bloodstained kerchief. ‘Watch!’ he instructed her, wadding it into a ball and tossing it out into the pool.
Royan screamed with horror as the waters boiled with the long fleeting shapes. One of them wriggled half its monstrous length out on to the ledge, before fl
opping back. It left a shining trail of silver slime across the black stones.
‘Taita has left his guard dogs to see us off,’ Nicholas remarked. ‘We are going to have to take care of those beauties before we can explore the entrance below the surface.’
The bamboo scaffolding that Sapper and Nicholas had built down the cliff was anchored in the niches that had been cut into the rock nearly four thousand years before. Taita had probably lashed his framework together with bark rope, but Sapper had used heavy-gauge galvanized wire, and the structure was strong enough to bear the weight of many men. The Buffaloes formed a living chain and passed all the material and equipment down the scaffolding from hand to hand.
The very first piece of equipment to reach the floor of the cavern was the portable Honda EM500 generator. Sapper connected it up to the lights that he had rigged along the foot of the cliff. The small petrol engine ran smoothly and quietly, but the amount of power it put out was impressive. The floodlights chased the shadows from the furthest corners of the cavern, and lit the deep rock bowl like a stage.
Immediately the mood changed. Everybody became more cheerful and confident. There was laughter and excited chatter from the chain of men on the scaffolding as Royan climbed down to join Sapper and Nicholas at the side of the pool.
‘Now that we know that they are working, switch off those lights,’ Nicholas ordered.
‘It’s so dark and gloomy without them,’ Royan protested.
‘Saving fuel,’ Nicholas explained. ‘No filling station on the corner. We only have two hundred litres in reserve, and although the little Honda is pretty economical we have to be careful. We don’t know how long we are going to need it in the tunnel.’
Royan shrugged with resignation, and when Sapper cut the generator the cavern was plunged once more into gloom and shadow. She looked at the dark pool and pulled a face.
‘What are you going to do about those horrid pets of yours?’ she demanded, glancing at Nicholas’s bandaged right hand.
‘Sapper and I have worked out a plan. We thought of trying to empty the pool completely, using a bucket chain. But the amount of water still coming down the river bed makes that a poor choice.’
‘We would be lucky to hold our own against that flow, even working around the clock with buckets,’ Sapper grunted. ‘If only the major had thought to bring along a high-speed water pump—’
‘Even I can’t think of everything, Sapper. What we are going to do is to build a small coffer dam around the underwater opening, and bale that out with buckets.’
Royan stood back and watched the preparations. Half a dozen of the empty mesh gabions were carried down the scaffolding and placed at the edge of the pool. Here they were partially filled with boulders that the men gathered up from the river bed. However, the gabions were not filled so full that they became too heavy to handle. There was no front-ender down here to move them around, and they would be forced to rely on old-fashioned manpower. There was just sufficient of the yellow PVC sheeting left over to wrap around each gabion and render it waterproof.
‘What about your eels?’ Royan was fascinated by these loathsome creatures, and she hung well back from the edge of the pool. ‘You can’t send any of your men in there!’
‘Watch and learn.’ Nicholas grinned at her. ‘I have a little treat in store for your favourite fish.’
Once all the preparations for the construction of the coffer were complete, Nicholas cleared the cavern, sending Royan and Sapper and all of the men up the scaffolding. He alone remained at the edge of the pool, with the bag of fragmentation grenades that he had begged from Mek Nimmur slung over his shoulder.
With a grenade in each hand, he hesitated. ‘Seven-second delay,’ he reminded himself. ‘Quenton-Harper dry flies. More effective than the Royal Coachman!’
He pulled the pins from each of the grenades and then lobbed them out into the middle of the pool. Quickly he turned away and hurried to the furthest corner of the cavern. He knelt with his face to the rock wall and covered his ears with both hands.
Squeezing his eyes shut, he braced himself. The rock floor jumped under him and the double shock waves from the explosions swept over him in quick succession, with a savage power that drove in his chest and stopped his breath. In the confines of the chasm the detonations were thunderous, but his ears were protected and the deep water of the pool absorbed much of the blast. A twin fountain of water shot high into the air and splashed against the cliff above his head. It poured down in a sheet over him, soaking his clothing.
As the echoes died away, he stood up. His hearing had not been adversely affected, and he had suffered no injury other than the shower of cold water. Back at the edge of the pool the water shimmered with movement. Scores of the great eels flopped and writhed on the surface, flashing their white bellies as they twisted. Many of them were dead, their bellies burst open, floating inert, while others were merely stunned by the blast. Knowing how tenaciously they clung to life he suspected that they would soon recover, but for the time being they were no longer a danger.
He bellowed up toward the top of the cliff. ‘All clear, Sapper. Send them down.’
The men came swarming down the scaffolding, amazed by the carnage that the grenades had wreaked in the pool. They lined the bank and began to fish out the bodies of the dead eels.
‘You eat them?’ Nicholas demanded of one of the monks.
‘Very good!’ The monk rubbed his belly in anticipation.
‘Enough of that, you greedy perishers.’ Sapper drove them back to work. ‘Let’s get those gabions in place before they wake up and start eating you.’
With a bamboo pole Nicholas sounded the depth of the water that covered the entrance to the shaft, and found that it was well over the height of a man’s head. They were forced to roll the gabions down into it, and complete the filling once they were in position. It was difficult and taxing work, and took almost two days to complete, but at last they had built a half-moon-shaped weir around the underwater entrance, walling it off from the main body of water in the pool.
Using leather buckets and clay tej pots the Buffaloes began to bale out the coffer and scoop the water over the wall into the main pool. Nicholas and Royan watched with silent trepidation as the level in the coffer fell and the opening in the cliff was gradually revealed.
Very soon they were able to see that it was almost rectangular, about three metres wide by two metres high. The sides and the roof had been eroded by the rush of water through the opening, but as the level fell lower they could see the remains of shaped stone blocks that had probably once sealed the opening. Four courses of them still stood where the ancient masons had placed them across the threshold of the opening, but the others had been torn out by thousands of years of flood seasons and thrown into the tunnel behind, partially blocking it.
Eagerly Nicholas climbed down into the coffer. It was not yet empty, but he could not control his impatience. The water was knee-deep as he crawled forward into the opening, and with his bare hands tried to shift some of the rock debris that choked it.
‘It’s definitely some sort of shaft,’ he shouted back, and Royan could not restrain herself either. She came slithering and sloshing down into the coffer, and pushed into the opening beside him.
‘There’s an obstruction,’ she cried in disappointment. ‘Did Taita do that deliberately?’
‘Might have,’ Nicholas gave his opinion. ‘Hard to tell. A lot of this rubble and flotsam has been sucked in from the main flow of the river, but he might have filled the tunnel behind him as he pulled out.’
‘It’s going to take a tremendous amount of work just to clear it enough to find out where this passage leads to.’ Royan’s voice had lost its ring of excitement.
‘I am afraid it is,’ Nicholas agreed. ‘We are going to have to clear every bit of this rubbish by hand, and there won’t be time for the niceties of formal archaeological excavation. We are just going to rip it out.’ He clambered back out of the coffe
r, and reached back to hand her up the bank. ‘Well, at least we have the floodlights,’ he added. ‘We can keep the men working in shifts, night and day, until we get through.’
‘They have dammed the Dandera river,’ said Nahoot Guddabi, and Gotthold von Schiller stared at him in astonishment.
‘Dammed the river? Are you certain?’ he demanded.
‘Yes, Herr von Schiller. We have a report from our spy in Harper’s camp. He has over three hundred men working in the gorge. That is not all. He has air-dropped huge amounts of equipment and supplies. It is like a military operation. Our spy tells us that he even has an earth-moving machine, some sort of tractor, which he has brought in.’
Von Schiller looked across the table at Jake Helm for confirmation, and Helm nodded. ‘Yes, Herr von Schiller. That is true. Harper must have spent a large amount of money. The air charter alone could have cost him fifty grand.’
Von Schiller felt the first stirrings of real passion since the urgent satellite message had summoned him from Frankfurt. He had flown directly to Addis Ababa, where the Jet Ranger had been waiting to carry him to the Pegasus base camp on the escarpment above the Abbay gorge.
If this was true, and he did not doubt Helm’s word, then Harper was on to something of enormous importance. He looked out of the window of the Quonset hut to where the Dandera flowed down the valley below the base camp. It was a large river. To dam that volume of water would be an expensive and difficult project in this remote and primitive situation – not a project to be taken on lightly without the prospect of substantial reward.
He felt a reluctant admiration for the Englishman’s achievement. ‘Show me where he has placed his dam!’ he ordered, and Helm came around the table to stand beside him. Von Schiller was standing on his block, and their eyes were on the same level.
Helm bent over the satellite photograph and carefully marked in the site of the dam. They both studied it for a minute, and then von Schiller asked, ‘What do you make of it, Helm?’