Of the race back through the night, I have only the most feverish recollections. I knew we were flying faster than ever before, for the fuselage was throbbing madly and you had a feeling that to escape an awful strain put upon it, the engine was trying to tear itself loose. And then you thought of the need for this speed. Had I been careless with the electric torch? Had we been seen? Might not even now the enemy be after us? Perhaps a telephone call from the battery down to the trenches where the muzzle of an aeroplane gun was tilted to the sky. Or had they telephoned their own aeroplanes to put up after us? Why the speed that Hals evidently deemed necessary? You knew, too, that somewhere down there, shells from the German batteries were whining towards the enemy's positions. You knew, too, that to reach the earth, you would have to bolt down through this battle-filled sky. The chances were one in five thousand that we would be in the line of our own shell fire. You did not like to think of that one chance. The machine had ceased to shake. I imagined that Hals was looking down on all sides. The wind, certain signal of a turn, struck my cheek. The slow swinging circles began as before. And then, just upon sighting the French battery, Hals suddenly drove the machine forward. Off to the left, what had seemed an unnaturally bright point of light grew incredibly fast into a circle of light and beside it a smaller circle, and their circumferences seemed to be restlessly moving, intersecting here and there with exasperating frequency, although gradually becoming steadier and finally becoming almost concentric, intersecting not at all, the smaller though seeming to have moved in front of the larger, shifting from side to side, although never touching the outer fiery rim. And suddenly I remembered the two circular frameworks, fitted with the electric bulbs, in the field by the shrapnel-scarred willows and I recalled the explanation of them, that they were guide posts for an aviator at night, and that once he had them concentric, he knew that he was flying true to his landing field.