THE CARNIVORE
As Forrester mounted higher into the chimney, he worked with ever increasing caution. To allow the rays to break a passage 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 passing 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 passage 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 transmutation.
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 passage 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."