"Well," he said, "I had a peach of an observation post up in the front line. It was an old derelict mill-wheel affair—one of those contraptions you see on the end wall of every farm-house in this country, with a poor brute of a mongrel dog inside, treadmilling away to work a churn, or play the pianola, or something. It lies out flat in front of C Company's sector, on top of a little rise, looking like nothing at all. You know it?"
"Yes," I said. "It has been there for months; it is one of the accepted features of the landscape by this time."
"That's right; the Boche has never suspected it. Well, I have been using it as an O. Pip for six weeks. There is a private covered sap leading out to it, and once you're inside you can stand in a pit, with your little circular peep-show all round you. Why, through one loophole I can see right away to Beaumont Hamel! Now, as you know, ten days ago we handed over to the Late and Dirties. This morning, when I went up into the line to see about taking over again to-morrow, what do you think I found—in my own special private O.P.?"
"I don't know," I said. "A hairpin?"
"Uncle Alan, for the Lord's sake don't play the fool! I'll tell you what I found; the whole floor of the post—my post, mind you—was covered with empty cartridge cases! Some Late-and-Dirty perisher had been in there with a rifle, firing volleys—no, salvoes—out of it! With an oily barrel, too, I'll bet! Of course the Boche has the place registered now; and next time there is any general unpleasantness brewing, up it will go! And I hope the Late-and-Dirty dog who gave it away will be inside, that's all!"
"It's rotten luck, I admit, boy. But in this case it doesn't particularly matter. In a day or two, we hope, your observation post will be far in rear of us. Perhaps some clerkly gentleman from the base will be making his nest therein."
Roy's face brightened suddenly.
"When do we push off?" he asked eagerly.
"That is a secret known only to the powers above. But I shouldn't be surprised if it were to-morrow, or the next day. The Colonel is away at a Brigade Conference now—the last, I dare say. He will probably call an officers' meeting when he comes back."
"Is Kilbride with him?" asked Roy quickly.