"No, sir. There must be some other reason."
"Yes, and the reason is, I think, a change of wind which is bringing on a dense fog."
"You are quite right, sir," added the other, after regarding the air and sky for some ten seconds. "There has been a sudden change of wind, and a dense local fog is coming up from the valley. The whole landscape will be blotted out in a few minutes."
"You're right, Grenfell," replied the officer. Then, turning to his orderly-sergeant, he called out:
"Pass the order for the men to stand-to! There is no telling but that the Boches may come over the top with the fog, and try to surprise us."
"Yes, sir," came the reply smartly, and the sergeant, saluting, disappeared along the trench, calling out the men from the dug-outs, and ordering a general "stand-to."
The chance was too good to be lost. Cowdie gave Brat a dig in the ribs, and whispered to him,
"Now is the time. See, the fog thickens, and it is nearly up to the wrecked aeroplane. Let's go over, or the Boches will be there first. They're sure to try it on. What say you?"
"I'm with you, old man, but it will be an awful job. Have you got your revolver loaded, for we've got nothing else?"
"Yes," replied his chum, feeling that his weapon was safe in the leather case, which hung at his left side.