That vast modern battle was not one in which, as in those of our fathers’ time, the decisive moment was grasped by the eye, and the decisive manœuvre conducted upon a field actually seen by the man deciding it. In that vast modern battle the critical moment was the end of calculation infinitely complex and stretching back for days; yet there was, in this moment of the late afternoon, on that Wednesday, essentially the same process maturing in a length of days which had with the great Napoleon matured in an hour; and what was about to be done was essentially the same as what Marlborough had done at Blenheim, when he drew that heavy phalanx of white-coated German cavalry from the right, under the heights, and launched it at the French left centre and decided Blenheim; for the enemy line, though still advancing, was stretched to its utmost, was breaking: the gap in the German line had been perceived, and proved fatal to the Germans. The general officer returned from his ride a little after six o’clock. He sat in the room of a private house, which during the last twenty-four hours had been the conning tower of the fight. He had the great map before him, scored with rough chalk. He saw through the tall windows before him the lowering sky. He received minute by minute the telephone messages, and marked their news in sharp pencil jabs upon the sheet. The dull noise to the north was the same; the reports pouring in from the front showed little change, but that little change was as significant as the slight movement after slack water in a harbour, when the tide begins to turn. It was still full daylight; the storm had broken on those northern hills; there were lightning flashes against the dead cloud, and the noise of distant thunder mingled with the ceaseless thudding of the guns. The general ceased his labour and could lean back in his chair, resting his eyes from the map, and make certain that the thing was accomplished. An order had been given upon the enemy’s side, and it was an order for retreat.... The evening fell, the rain drove through darkness, the thunder lessened, grumbled and withdrew. None slept. All followed the more distant, the withdrawing signal of the artillery. The reserve troops came marching through, hurrying to the north. The tide had indeed turned. The general officer was mounted again with his few companions and riding north with the rest through the storm. Before midnight a great glare was seen on the horizon, blurred with rain. He informed himself what it was, and heard it was the station of La Fère Champenoise burning: the enemy had abandoned it three hours before. And still they went northwards, and still the far noise of the guns retired before them, miles away. * * * * *