CHAPTER XV

THE MOLES

"Give me my bone!"

Forrester puzzled over the words. They seemed merely absurd. What could their meaning be? It was a joy to know that Mackenzie or Jackson was above, and had discovered the place of imprisonment; but they must know little about it, after all, or they would be aware that it was impossible to send them an answer. Yet they must expect an answer; they would not have sent a message, mysterious as it was, unless they looked for at least an acknowledgment that it had been received. It occurred to him that the cleft might be used as a speaking tube: but a moment's consideration told him that it would be unwise to put this to the test. His voice might be heard by an enemy!

Beresford was so much exhausted after the day's work that Forrester did not mention the strange discovery to him that night. But the next day was an off day for him, and in the afternoon, after he was somewhat restored by rest and food, Forrester showed him the bone and the paper. The effect was electric. A look of eager hope dawned in the tired eyes. A murmur of thankfulness broke from his lips, and he lay for a while thinking.

"We have nothing we can write with," he said at length.

"Nothing at all. My pockets are empty," replied Forrester.

"Not even a pin?"

"No. Wait, though!" He felt along the edge of his waistcoat. "Yes, by Jove! I've one solitary pin. They would naturally overlook that."

"Prick the words through the paper."

"But what words?"

"Something that won't give anything away if the paper falls into the wrong hands. 'Give me my bone!' Answer, 'Take it!' Put the paper in the bone, fill up with dust, and replace it in the cleft when you get a chance. Leave the rest to our friends above."

The guard kept by the priest and the negritos was little more than a form. The abject condition of the Chinese prisoners precluded any likelihood of revolt. Consequently no real watch was kept at night, and the only risk was that an unusual sound might awaken one of the three somnolent figures at the entrance. Forrester was careful to move very quietly when he returned to the cleft that night, though after all there was little chance of a slight sound from the inner cavern reaching the priest's ears.

On reaching the cleft he looked in eagerly for the string which he half expected to find there. He was not disappointed. A few feet from the opening, but within easy reach, lay another bone, with a string attached. He replaced this by the bone containing the paper, and stole back to his friend. The second bone held no message.

"We shall hear from them again to-morrow," said Beresford hopefully.

Next night, when Forrester visited the cleft, he found the bone on the end of the string, untied it, and hurried back with it to Beresford. Shaking out its contents, he found a somewhat larger screw of paper, enwrapping a sharpened stick of charcoal. On it, when opened out, he read: "String 65': hole 3' x 10": grated: where are you? Reply at once. M."

"He evidently thinks communication safe at night," said Beresford. "We can't tell him everything. Just write: 'Cavern. Boring chimney through roof. More to-morrow.'"

Forrester wrote the message, adding 'B. is here,' replaced the paper, and returning to the cleft, tied the bone again to the string. It occurred to him to give a slight tug. The string gave slightly, then stretched taut. It was evidently fastened to something above.

It was long before the Englishmen fell asleep that night. They discussed in whispers the information they had gained, and their future course of action. They could not but conclude that the cleft, narrow as it was, was the avenue by which the negrito had escaped; but what was possible to his diminutive frame was impossible to them. The grating had probably been placed over the hole after his escape was discovered, to prevent a second attempt. It was clear that the cleft was not perpendicular, or the little man could hardly have climbed up it. If they could ascertain the angle of its slope, they might calculate the vertical distance, and learn how long their chimney through the roof of the inner cavern must be made. They had no means of discovering this fact, which would have been so useful to them; but it seemed probable that, allowing for the steepest practicable slope, the chimney must be pierced for at least forty feet before it reached the surface.

By gradually lengthening the bamboo pole, and clearing the dust from the sides of the chimney, they had already extended the range of the rays nearly twenty feet above the roof, and more than thirty feet above the floor of the cavern. They had now no more bamboo rods; the pole could not be lengthened further; it was impossible to remove the dust at a greater height without a ladder to stand on. But, with communications open, a ladder might no longer be an impossibility. With a knife and some stout string they might form one of bamboo, and still leave enough for a pole wherewith to continue their work of removing the dust. Forrester resolved to ask for these articles at the first opportunity.

Beresford pointed out the importance of letting Mackenzie know the spot at which the chimney, when completed, would reach the upper air. It might prove to be in the very quarters of the enemy. In that case the chances of escape would seem to be remote indeed. But Mackenzie was cautious as well as shrewd, and with this necessary information in his possession he would know how to direct his own course, and what advice to give his friends below.

Accordingly, next day Forrester carefully paced the distance between the cleft and the pit in the inner cavern. Allowing as accurately as he could for the windings of the passage, he gauged the length to be approximately fifty yards in a straight line. At night, he found on opening the paper secreted in the bone that Mackenzie had anticipated him. "Cleft--?--> chimney." he read. He crossed out the query and wrote "50 yds.: cleft on right," adding: "Send knife + stout string." He returned to the cleft several times during the night in the hope of finding the things asked for; but it was not until the next night that they came: a large kitchen knife such as is used in boning meat, and about a dozen yards of thin hempen cord.

The work on the chimney had been perforce interrupted for several days, much to Beresford's benefit. The less prolonged exposure to the noxious atmosphere of the inner cave, and the new hope engendered in his heart by the knowledge that something was in progress above, effected a decided improvement in his physical and mental condition. His fear now was that he would be summoned again to the Old Man, and condemned without reprieve, before the chimney was complete. He resolved, if he were sent for, to persist in his refusal to translate the tablet, in the hope that the Old Man would spare him for yet further coercion.

Forrester set to work on the ladder as soon as possible after the knife came to hand. At night, in the passage, he cut short lengths of bamboo as rungs, and knotted them firmly to the two uprights with the cord. It was a crazy structure at the best, and he had a nervous dread lest, if he fell, he should break through or displace the slab over the pit, and be turned instantly to dust. But an experimental ascent against the wall and the cavern somewhat reassured him as to the ladder's stability, and setting its top in the cavity above the pit, he mounted and resumed the work of scouring away the dust overhead.

From that moment they applied themselves to the task with unremitting energy. As soon as their fellow prisoners were torpid in the heavy sleep that was the only alleviation of their lot, the Englishmen stole from their place, and laboured until their endurance gave out. Forrester spared Beresford as much as possible, and often undertook the double work, alternately lifting the slab to release the rays, and, when it was lowered, climbing to remove the dust. Each knew he carried his life in his hands, for the ladder could not be entirely hidden. If any priest should chance to visit by day the passage in which they laid it, he could not fail to observe it, and then their fate was sealed. But, judging by past experience, that risk was slight; and to disregard it was the only way to success.

Every now and then Forrester reported progress to his friends above. The length of the chimney increased about eighteen inches a day on the average; if, as they had calculated, there remained--before they constructed the ladder--twenty feet of rock to pierce, in a fortnight they should arrive at or very near the surface. Meanwhile they received no news of what was happening above ground. Mackenzie did not reveal his plans; perhaps, they thought, he had formed none, but was biding his time until the chimney was nearly completed. His messages were brief words of encouragement, assurances that all was well, and the news that he was in touch daily with Jackson, Sher Jang, and Hamid Gul.

Rather more than a week after the first use of the ladder, Forrester made the alarming discovery that he could no longer reach the top of the cavity with the outstretched pole. This threatened the stoppage of the work, for neither pole nor ladder could be lengthened. He did not mention the matter to Beresford, who by this time had ceased to work on the chimney. When he had transmuted the due number of plates, he was too much fatigued to endure the strain any longer, and Forrester persuaded him that he must conserve his strength for what might ensue when the chimney was completely pierced. Anything that might throw him back was to be avoided.

Forrester puzzled over the baffling problem that now confronted him. Time and again he stood looking up into the cavity, trying to conceive of a means by which the top might be reached. It was two days before he hit upon a possible solution. If he could cut notches in the walls of the chimney, and insert in them cross-bars of bamboo, he would be able to raise himself successively to heights from which the rock above would be within reach of the pole. To obtain material for the cross-bars he would have to shorten the pole; the difficulty was the notches: how could they be cut with no tool but a knife? Standing on the ladder, he tried the point of the blade on the rock, and found that this, while not very hard, was not friable enough to be excavated by so pliant a tool.

His thoughts turned at once to Mackenzie: perhaps he could find a more serviceable instrument. That night he placed in the bone the following note: "Work stopped: send a chisel." Next night he found in the bottom of the cleft, not a chisel, but a bar of iron slightly pointed at one end. Accompanying it was a note: "Hope this will serve. Let me know when near surface."

This implement he found to answer his purpose sufficiently well. From his perch on the top rung of the ladder he worked out two holes in the rock on opposite sides of the chimney; then with the knife he cut the proper length of bamboo, and thus fashioned a cross-bar on which he could stand to repeat the same operation higher up. In this way he made a series of steps enabling him to brush the dust, as before, from the top of the cavity after each employment of the rays. Only then did he acquaint Beresford with the difficulty and the manner in which it had been overcome.

The progress of the work was necessarily slower now. The cross-bars had to be removed after each ascent; otherwise at the next opening of the pit they would have been instantly destroyed. But the piercing went on steadily, and Forrester felt sure that, unless his calculations were very much out, his pole would in a few more days penetrate the roof of the chimney, and emerge through a hole in the floor of whatever room was immediately above him.

"Be very cautious," Beresford urged, when he learnt this good news. "To break through prematurely might be fatal to us all. Tell Mackenzie how things are, and ask for instructions."

"Yes. We shall have done our part. The rest will lie with him. I wonder what old Mac has been doing all this time?"