He crept through the hedge and crouching behind it ran to the spot where they had found the open trap-door upon that memorable occasion three nights before. There was nothing to be seen. The ground presented an absolutely unbroken appearance, so far as they could make out in the moon's rays.
"Clever devils!" snapped out Cleek, in angry tribute. "We'll have to use artificial light after all; but keep your torch light on the ground. It won't do for any one to spot us just now."
For perhaps a moment or two they explored the ground inch by inch, crawling round in the long grass upon their hands and knees, until a little tuft of brown earth sticking up through a piece of turf, like the upturned corner of a rug, showed them what they were looking for. With infinite care Cleek lifted up the square of turf and set it upon one side. The sight of the flat dark surface of the trap-door rewarded them. He ran his fingers along the two sides of it, and discovered a bolt, shot this, and then catching the iron ring once more in his hands, swung the top upward and laid it back upon the grass.
A minute more found them once more in the cavernous, breathless depths. Cleek handed the torch to Dollops.
"You hold that while I do a bit of sketching," he said, fidgeting in his coat-pocket for his fountain-pen. He then snapped open the flap of the note-book and began to sketch rapidly as they moved forward. Cleek was an adept in drawing to scale. The thing took shape as they continued their progress, keeping this time to the left instead of to the right. Cleek paced off the distance and stopped every now and then to check up results.
The place was as silent as the grave. Obviously no one was about here upon these nights when there was no loading and unloading going on. In that, at least, chance had been a good friend to them. They were going to make the most of it. Through little runways, narrower than the main route, and so low that they had to bend their necks to get along in safety, they went, measuring and examining. Every few yards or so they would come upon another little niche, stacked high with sacks of a similar hardness to those others back there at the beginning of their journey. Cleek prodded one with his finger, hesitated, then slipping out a penknife, slit a fragment of the coarse sacking and inserted his thumb....
He pulled it out with a look of astonishment upon his face.
"Hello, hello!" he exclaimed. "So that's it, is it? Gad! This is the approved hiding-place! Then those tubings—Dollops, just a little more of this wearisome search, just a few telephone calls to be made, and I believe I shall have untied at least one part of this strange riddle. And when that knot is unfastened, it will surely lead me to the rest.... Go on, boy."
They went on, stepping carefully, and hesitating now and again to listen for any sound of alien footsteps. But the place might have been the grave for any sign of human habitation that there was. They had it to themselves that night, and made the most of it.
For some time they walked on, taking the road that most appealed to them, and in the maze must surely have retraced their own footsteps. Of a sudden, however, they broke into a sort of rough stone passage, with concrete floor that ran on for a few yards and ended at a flight of well-made stone steps, above which was a square of polished oak, worm-eaten, heavily-carved, and surely not of this generation's make or structure.