"The better part of a platoon of the Rutlands is missing. They hold the trenches in front of us, you know. Well, they got up a night raid, and penetrated the Huns’ first line: came back with a handful of prisoners and no casualties to speak of. But when they took stock, something over forty men of this platoon were missing." "They went too far, I suppose, and were cut off. Very bad luck." "If they’re prisoners! Whatever happens to me, I hope I shan’t be a prisoner. These raids are the order of the day now; I suppose they’re useful. At any rate they give our fellows something to do." At this moment Burton started as the words "Battery action" came from somewhere in a roar like that of a giant. "Megaphone!" cried Adams, jumping up. The officers rushed into the gun-pit. The men who had been working outside came racing in. In a few moments another order was shouted through a megaphone by the man in the telephone room--a shell-proof cave hard by. "Target M--one round battery fire." Captain Adams took up a map of the German trenches, and with a rapidity that amazed Burton, angles and fuses were adjusted, and in a few seconds a shell went whistling and screaming towards its invisible target miles away. Cay had gone to the wireless instrument in the corner, and sat with the receiving telephones at his ears. "Range right; shell dropped quarter-mile to the left," he called presently. New adjustments were made; the gun fired again. "How’s that?" asked Adams. It seemed only a few seconds before Cay, repeating the message he had received from the invisible aeroplane scouting aloft, replied: "Got him!" A moment later he added: "New battery----" He broke off: the burring of the instrument had ceased. He tried to get into communication again, but failed. "Ask O.P. if they’ve seen the ’plane," he called to the telephonist. Presently came the answer: "Went out of sight behind a wooded hill. Afraid a Hun ’Archie’ has brought it down." Meanwhile the order "Break off" had been received. The immediate task of the battery was accomplished. II The officers returned to their dug-out. "Your colleague hasn’t had your luck, Burton," said Adams. "It’s more than a pity. He had evidently spotted a fresh battery. The Huns will have time to conceal it unless some one else spots it and tips us the wink." They went outside and scanned the sky. No aeroplane was in sight. "I think I’d better go up," said Burton. "I’m off duty to-day, but it would be a pity to lose the chance. The new battery must have been visible from where he saw your target. I ought to be able to find it if I go at once." "A good idea! We might smash it before it gets to work. You’d better ’phone your flight commander. I’ll lend you my trench map." Burton hurried to the telephone room. In a few minutes he returned. "O.K.," he said, "but I’ll have to go alone. My observer’s away, and there’s no one else handy."