He turned to descend softly from where he had climbed to, and his foot slipped on the weather-worn stone, so that he made a loud scraping sound in saving himself from a fall; but not so loud that he was unable to hear the scuffling of feet close at hand, followed directly after by dead silence. His finger was on the trigger of his pistol, and he was within an ace of firing in the direction of the noise, but refrained, and contented himself with walking as sharply as he could towards it with outstretched hands, for overhanging rocks made the place he was in darker than ever, and he was reduced to feeling his way. Then stopping short with a sense of danger being close at hand, he gave the customary challenge, to have it answered from behind him; and the next minute he was face to face with a sentry. "I thought I heard something, sir," said the man. "Then it was you?" "No, no," said Dickenson; "I heard it too--a low chirp like a bird." "No, no, sir; not that--a sound as if some one slipped." "Yes, that was I," said Dickenson; "but there was a chirp. Did you hear that?" "Oh yes, I heard that, sir; and another one answered it." "And then there was talking." "Oh no, sir, I heard no talking. Sound like a bird; but I think it's a little guinea-piggy sort of thing. I believe they live in holes like rats, and come out and call to one another in the dark." "Well, perhaps it may be; but keep a sharp lookout." "I'll keep my ears well open, sir," said the man; "there's no seeing anything in a night like this." The sentry was able to put his visitor in the right direction, and Dickenson went on, forgetting the incident and wondering how Lennox was getting on; then about what the colonel would say to his ill-success; and lastly, the needs of his being filled up all his thoughts, making him wonder what he should get from the mess in order to satisfy the ravenous hunger that troubled him after his long abstinence. He reached the square at last, but not without being challenged three times over. Then making his way to the colonel's patched-up quarters, he was just in time to meet the patrol coming into the opening, their leader going straight to the mess-room, where the officers were gathered. "Any luck?" said Dickenson. "I was on the lookout for you up yonder till I couldn't see." "Yes, and no," said the officer. "Come on and you'll hear."