The aeroplane finally vanished, and the men returned to their cards, turning up the lamps again. Some ten minutes later the report of the gun was heard. It was fired at intervals for an hour, at varying distances; then the low rumble of the train approached. The watchers heard the door of the second shed creak. In a few minutes the train glided up, and entered the shed, into which, it being the middle one of the three, the Englishmen could not see from their present position. After a while the door was closed, and the gun crew joined their comrades. They were not accompanied by their officer, who had no doubt gone to more select and comfortable quarters elsewhere. After exchanging a few words with the cardplayers, the newcomers threw off their clothes and got into bed. "I should like to have a look into the other sheds," whispered Harry. "But the moon lights up the other side; and the----" "Don’t talk here," said Kenneth. "Come round to the back." Taking care not to displace loose stones, they crept along the wall and some distance into the quarry. "They can’t hear us here," said Kenneth, still, however, speaking in whispers. "I think we’ve found out enough. The place is marked on the map. Our gunners can shell it by map measurement." "Yes, but let’s have a look at the other sheds before we go. It won’t be safe to go into the moonlight, perhaps; but couldn’t we take a peep from the rear?" "The sheds are built right against the quarry wall. But we’ll go and see." They stole across the litter until they came to the back of the sheds. There they found that there was some chance of achieving their purpose. The wall of the quarry was very uneven, just as it had been hewn out. Consequently the back walls of the sheds did not fit flush against it; there was a space of varying width, but at its narrowest part wide enough to admit a man. Into this they crept. They discovered that this end of the sheds was in worse repair than the side they had already seen. Protected from the weather by the wall of the quarry, the timber had not been renewed. There were many gaps, and when they touched the wood, its crumbling gave signs of dry rot. But the interiors of the second and third sheds were quite dark: it was impossible to distinguish anything within. Harry broke off several fragments of the dry wood without making any sound. "We can get in," he whispered. Kenneth hesitated. They had learnt enough for their purpose; it would be a pity to risk the failure of the whole enterprise. But youth is adventurous and confident. The voices of the men in the first shed would smother any slight sounds they might make; the sentry was at least a hundred and fifty feet away. "All right," he murmured.