A rope was speedily forthcoming, and fastening a fragment of rock to the end of it, Mackay carefully allowed it to descend. It came to a standstill in good time, however, showing that the bottom of the passage was barely three feet below the point where the rent had entered its wall. Mackay quickly proceeded to adjust the rope so that its extremity dangled just on the edge of the yawning gap, then he made it fast on the outside by coiling it several times round the top of the sundered rock.
"A man could pull himself out in a hurry by getting something to hold on to," he remarked, "an' it's just as well to be prepared."
This operation completed, Emu Bill wriggled himself down through the narrow opening, and holding on to the guiding-rope, quickly disappeared from view, while his companions on the surface waited expectantly for his report on his surroundings.
"Well, an' what do you make of it, Bill?" demanded Mackay, when the tension on the cable had slackened.
"I can't see a single thing," came the response. "It's dark as—as Hades, an'—howlin' blazes! but it does smell."
Without a word Mackay slid down beside his complaining comrade; the Shadow followed, then Jack, and lastly Bob squirmed down beside them. All was dark and oppressively gloomy in the strange passage, and the thin streak of light from the opening they themselves had made, only served to intensify the utter blackness which prevailed. They stood for a full minute without speaking, their ears alert for the slightest sound which might warn them of danger; but all was silent as a tomb.
"Now, boys," whispered Mackay, "we'll have a look at the inside o' that other doorway before we go any further." He led the way, staggering and stumbling, and Bob, following at his heels, became conscious that the floor of the tunnel was extremely muddy and wet. After a few steps Mackay paused. "I've got a bit o' candle in my pocket," he said; "I may as well strike a light."
The match spluttered feebly in his hand for a moment, and then went out, but on a second attempt he succeeded in getting the candle alight, and though it burned with a dismal blue flame, it illuminated the rocky cavern sufficiently for the adventurers to observe its structure.
They stood in a longitudinal chamber about eight feet high, and barely four in width. The roof fairly scintillated with beaded moisture, and the dank, cold walls were adrip with ooze. The bottom of the chamber, as they had already discovered, was a soft and clinging clayey formation. Mackay's trained eye immediately grasped the significance of the scene.