They were absolutely still for a full minute, but there were only the familiar sounds of the night.
"All right," said Paul. "Now you watch and listen while I dig down here and see what this is about."
"Why can't I dig, too?"
"Because it's better for you to watch. Besides, I want to dig so that I can put the earth back in a hurry, and fix this place so that it won't look as if it had been disturbed."
Then he fell to, working silently and quickly, like a mole, digging with his hands until his nails were torn and his fingers were raw and bleeding. But Paul did not mind that. He had already made a guess, and a shrewd one, as to the meaning of this strange discovery that they had made. It was not long before he found that the steel plate extended for only a short distance. Around this, and spreading beneath it, was a bed of cement. As soon as he had satisfied himself of that, using Arthur's flashlight, Paul stopped digging, and began carefully to replace the earth. Then, calling on Arthur to help him, he trampled down the earth.
"There!" he said. "I don't believe anyone would know we had been here, unless they were suspicious already."
"But what is it?" asked Arthur. "Paul, tell me!"
"I'm going to, Arthur. Don't worry. But come away from here. We don't want to be caught around here—and, besides, there's still a good deal for us to do."
Swiftly they made their way to the road, away from the cottage and the field where they had made their discovery.
"Now!" said Arthur, after a little distance had been covered, stopping short. "I won't go a step further until you tell me what that place is meant for!"