By day, the slightest movement of the enemy is easily and instantly detected. Light keeps the combatants to the warrens which protect them from shell and bullet-fire. At night there is no telling what mischief the enemy may be up to; you must depend upon the ear rather than the eye for watching. Then the human soldier-fox comes out of his burrow and sneaks forth on the lookout for prey; both sides are on the prowl. "Trained owls would be the most valuable scouts we could have," said the young officer. "They would be more useful than aeroplanes in locating the enemy's gun-positions. A properly reliable owl would come back and say that a German patrol was out in the wheatfield at such a point and a machine-gun would wipe out that patrol." We turned into a side trench, an alley off the main street, leading out of the front trench toward the Germans. "Anybody out?" he asked a soldier who was on guard at the end of it. "Yes, two." Climbing out of the ditch, we were in the midst of a tangle of barbed wire protecting the trench front, which was faintly visible in the starlight. There was a break in the tangle, a narrow cut in the hedge, as it were, kept open for just such purposes as this. When the patrol returned it closed the gate again. "Look out for that wire--just there! Do you see it? We've everything to keep the Boches off our front lawn except 'Keep off the grass!' signs." It was perfectly still, a warm summer night without a cat's-paw of breeze. Through the dark curtain of the sky in a parabola rising from the German trenches swept the brilliant sputter of red light of a German flare. It was coming as straight toward us as if it had been aimed at us. It cast a searching, uncanny glare over the tall wheat in head between the trenches. "Down flat!" whispered the officer. It seemed foolish to grovel before a piece of fireworks. There was no firing in our neighbourhood; nothing to indicate a state of war between the British Empire and Germany; no visual evidence of any German army in France except that flare. However, if a guide who knows as much about war as this one says you are to prostrate yourself when you are out between two lines of machine-guns and rifles--between the fighting powers of England and Germany--you take the hint. The flare sank into earth a few yards away, after a last insulting, ugly fling of sparks in our faces. "What if we had been seen?" "They'd have combed the wheat in this part thoroughly, and they might have got us." "It's hard to believe," I said. So it was, he agreed. That was the exasperating thing. Always hard to believe, perhaps, until after all the cries of wolf the wolf came; until after nineteen harmless flares the twentieth revealed to the watching enemy the figure of a man above the wheat, when a crackling chorus of bullets would suddenly break the silence of night by concentrating on a target. Keeping cover from German flares is a part of the minute, painstaking economy of war.