And now comes the odd quarter of a mile of communication trench. It is very narrow, for the enemy can enfilade it, and it is paved with brushwood and broken bricks, and a little drain, that is meant to keep the floor dry, runs along one side of it. In one place a man steps off the brushwood into the drain, and he falls headlong. The others behind have no time to stop themselves, and a grotesque pile of men heaps itself up in the narrow, black trench. One man laughing, the rest swearing, they pick themselves up again, and tramp on to the firing line. Here the mud is even worse than on the plain they have crossed. All the engineers and all the trench pumps in the world will not keep a trench decently dry when it rains for nine hours in ten and when the trench is the lowest bit of country for miles around. The men can do nothing but "carry on"--the parapet must be kept in repair whatever the weather; the sandbags must be filled however wet and sticky the earth. The mud may nearly drag a man's boot off at his every step--indeed, it often does; but the man must go on digging, shovelling, lining the trench with tins, logs, bricks, and planks in the hope that one day he may have put enough flooring into the trench to reach solid ground beneath the mud. All this, of course, is only the infantryman's idea of things. From a tactical point of view mud has a far greater importance--it is the most relentless enemy that an army can be called upon to face. Even without mud and without Germans it would be a very difficult task to feed and look after a million men on the move; with these two discomforts movement becomes almost impossible. It is only after you have seen a battery of field artillery on the move in winter that you can realise at all the enormous importance of good weather when an advance is to be made. You must watch the horses labouring and plunging in mud that reaches nearly to their girths; you must see the sweating, half-naked men striving, with outstanding veins, to force the wheels round; you must hear the sucking cry of the mud when it slackens its grip; and you must remember that this is only a battery of light guns that is being moved. It is mud, then, that is the great enemy. It is the mud, then, and not faulty organisation or German prowess that you must blame if we do not advance as fast as you would like. Even if we were not to advance another yard in another year, people in England should not be disheartened. "Out there" we are facing one of the worst of foes. If we do not advance, or if we advance too slowly, remember that it is mud that is the cause--not the German guns. IV THE SURPRISE ATTACK "Do you really feel quite fit for active service again?" asked the President of the Medical Board.