The dull thud of footsteps brought them to a sudden halt, and they crouched under the bridge, listening anxiously as the walker pa.s.sed over their heads. They caught a glimmer of light, and as the footsteps receded, Mackenzie peeped out, and saw a priest, swinging a small lantern, moving towards a building a good distance on their left. He entered it, and disappeared.
"Last man out!" whispered Hamid.
After waiting a few minutes, they continued their way along the stream.
It flowed through a wide inner enclosure, in which were scattered a number of small structures like summer-houses. Two slight bridges spanned the stream, and here and there were irregular ma.s.ses which in the darkness could not be clearly distinguished, but which appeared to be rockeries. Quaintly shaped bushes outlined their dark forms against the walls of the distant buildings. Mackenzie concluded that this was either the Old Man"s private garden, or the garden of the priests. Hamid could not tell him; he had been strictly forbidden to stray in this direction, or even to look over the low wall that surrounded the enclosure.
The watercourse was not straight. It turned now to the right, now to the left; its general course carried it obliquely across the garden, towards the angle of the wall. Thus the buildings on the right were not parallel with it. Mackenzie stopped, to take his bearings. Hamid pointed out his own quarters, the kitchen adjoining, and the wall of the pa.s.sage connecting with the dwelling of the Old Man. The paG.o.da reared itself high above the other buildings. Beyond it lay the barrack-like lodgings of the first order of priests; those of the second order were on the opposite side of the enclosure, and were approached by means of the bridges.
"How far along the pa.s.sage is the grating?" Mackenzie asked in a whisper.
"About half-way, sahib."
"And on which side?"
"Side nearest us, to be sure, sahib."
"Wait here for me, and hold this."
He placed in Hamid"s hands the end of a coil of string, climbed over the embankment, and made his way with stealthy speed towards the middle point of the pa.s.sage wall, as nearly as he could judge it, paying out the string as he went. On reaching the wall, he turned swiftly back, coiling the string round his finger. When he regained Hamid"s side, he knew that the distance between the wall and this point of the embankment was a little more than sixty yards. The chimney which his friends were cutting would reach the surface somewhere on the circ.u.mference of a circle of which the middle of the wall was the centre, and which would come within about ten yards of his present position. He followed that imaginary line with his eye. It pa.s.sed close to one of the summer-houses, ran across a bed of plants, then over the gra.s.s on which he had walked, touched the embankment some yards to the right, owing to the oblique course of this, and finally reached a point near the door of the cook"s lean-to. To gauge the position of the chimney more precisely was impossible, because, though he knew that it was on the near side of the pa.s.sage, he knew no more than that it was fifty yards from the grating.
Making a mental note of the course of the circ.u.mference on which lay the locus of the hole sometime to be pierced, he considered for a few moments whether to steal towards the door of the paG.o.da, and try to discover whether it was guarded. But by this time he was shivering with cold. His reconnaissance had not been unfruitful, and he decided to return at once to his hut. He parted from Hamid at the culvert, handed him the blanket, again entered his cold bath, and picking up his clothes, ran lightly over the ground to his lodging. Only on those two night expeditions had he taken off his clothes since his departure from the village in the forest.
Next morning Hamid handed him a note which he had drawn up in the bone.
It was the longest he had yet received: Forrester had grown bolder, more reckless, perhaps, with the lapse of time. It read: "Always light below. Can"t tell when it becomes dark outside. Give us a sign."
"Things are moving," he thought. "They are afraid of cutting through in the daylight. How in the world can I give them a sign? Hamid lets down the bone at all hours. Ah, well, I must think it out."
CHAPTER XVII
THE CARNIVORE
As Forrester mounted higher into the chimney, he worked with ever increasing caution. To allow the rays to break a pa.s.sage through before everything was ready for joint action with his friends above would be disastrous. Another possible mischance was even more alarming. The ground might cave in prematurely by its own weight, or the weight of somebody pa.s.sing over it. The result might be to hurl him on to the frail screen below, and through it into the pit.
To guard against such accidents he listened intently at each ascent, before he brushed away the protective dust. Once he thought he heard distant footfalls; another time the sound of running water. He wished that Mackenzie had been more communicative about what he was doing, and what he had discovered; but reflected that if his friend was silent, it was because, with Scotch canniness, he was determined to risk as little as possible, for the sake of all.
He waited patiently for the sign by which he would know when darkness fell in the open. The bone, no doubt, could be dropped only at uncertain intervals, as opportunity offered. Even if he knew that it would be let down precisely at the hour of sunset, he could not be sure of being then on the watch at the cleft, for it was not his duty to enter the inner cavern at all; his secret work there had been done only when guards and prisoners were asleep, and that was probably much later than sunset.
One day, Beresford, just before he had finished his task at the pit, and while Forrester was awaiting him in the outer cavern, noticed a trickle of water running from the inner pa.s.sage towards him. While he was still looking at it in surprise, wondering where it came from, it was reinforced by a sudden swell, which carried the tiny stream across the floor of the cavern in a direct course for the open pit. By the time it reached the brink it had almost exhausted its energy; but some of it flowed slowly on, and poured over. Instantly there was a terrific explosion, like the bursting of an immense inflated bag, accompanied by a flash of white light which for the moment wholly conquered the green.
Beresford was hurled against the wall of the cavern, and when he picked himself up, he saw that the force of the concussion had shut the screen down upon the pit, gripping the gold chain to which was suspended the plate in process of trans.m.u.tation.
It was all over in a moment; but Beresford had hardly recovered his senses when Forrester came hurrying into the cavern, through the cloud of dust which had followed the explosion, with Wing Wu and the priest in charge hard on his heels.
Forrester had just time to give a word of warning. When the priest arrived, Beresford had sufficient presence of mind to explain in Chinese that while the cover was lifted from the mouth of the pit there had been a loud bang. He did not mention the stream of water; it had now ceased to flow, and though its appearance had amazed him, and in his half-dazed condition he attached no definite meaning to it, he felt instinctively that it had a meaning for himself and his fellow prisoners.
The priest looked puzzled. The dust had set him coughing. He peered through it round the walls, remaining at a discreet distance from the pit, and thus failing to notice the dwindling trickle on the farther side. The atmosphere of the cavern, at all times unpleasant and oppressive, was stifling now. In a few moments everybody was retreating along the pa.s.sage to the outer cavern, Beresford remaining only to release the chain, draw up the plate, and lower the apparently uninjured screen firmly into its place. The negritos were just bringing in the evening meal.
"Are you hurt?" Forrester asked anxiously.
"Slightly bruised, perhaps; nothing serious."
"What on earth caused the explosion?"
"A trickle of water into the pit. Where it came from----"
"That was the sign!" exclaimed Forrester aloud, knowing that the priest could not understand him. But Wing Wu understood.
"What sign, sir?" he asked eagerly.
"Shall we tell him?" said Beresford.
Forrester hesitated for a moment.
"Not yet," he answered.
Wing Wu sighed, and turned away.
The priest at the entrance was joined by a second, drawn by the noise from the guard-room beyond the lake. They talked together for a few minutes, then the second man departed.
"He will tell the Old Man, no doubt," said Forrester to his companion.
"Yes; things are coming to a crisis. The water was our sign, no doubt.
It could hardly have been accidental. Mackenzie must have thrown a bucketful or two through the grating. It is dark outside at about the time of our last meal."
"Do you think the priests suspect us?"
"Who can say what goes on in their Chinese minds? The fellow didn"t see the water: that is pretty certain. But I am troubled. In the chimney you heard running water above you, you said?"
"I am almost sure of it--perhaps the stream that runs across the plateau."
"If our chimney pierces its bed, we are doomed. There is not the ghost of a chance for us. The explosion you heard will be as a popgun to a whole Dreadnought armament in comparison with the result if the cavern is flooded. I take it that the water which fell into the pit was instantly decomposed by the rays. Only a little trickled over the brink; yet the explosion was powerful enough to hurl me against the wall. If water pours down in any volume, the whole place will be shattered, and we shall be cremated instantly in one enormous flame."
"Will you go up the chimney yourself presently, and see if I was right?"
asked Forrester, aghast at the thought of this cataclysm.
"I will try. Thanks to you I am not nearly so much crocked as I was a few days ago. But we will wait a little longer than usual, to give the priest time to settle down if he is at all suspicious.... You were quite right, by the way, not to let me explain things to Wing Wu. He is so easily hypnotised that he might betray us at the first question. It will be time enough to tell him when our work is done."
Several hours later, they stole into the inner cavern, and when Forrester had placed the cross-bars in position, Beresford mounted the ladder, and climbed laboriously into the chimney from bar to bar. He carried the piece of pointed iron, with which he carefully probed the roof. Withdrawing the implement, he pa.s.sed his fingers along it from the pointed end downwards.
"We are very near the surface," he called down softly. "You have destroyed all the rock. The iron has gone through two or three inches of clay, and then into loose earth. We can"t risk employing the rays again. If the earth above collapsed en ma.s.se, it would smash through the screen and carry us with it into the pit. We must bore a hole gradually with the iron."
"What about the water?" Forrester asked.
Beresford listened intently, Forrester standing below with his hand on the ladder.
"Yes," said Beresford at length, "you are right. But it appears to be at one side, not directly overhead. Ah! there are footsteps. Listen!"