“Oh, they’ll come back safe and sound,” declared Andy. “They’ve just got to!” Yet behind it all the fun-loving Rover felt just as bad as any of them, but he was trying hard not to show it.
The boys were dropped off at the encampment, and then the girls continued on the way to Clearwater Hall. They were to remain at the Hall for the best part of a week longer, and then Mary and Martha were going to join their mothers and their aunt for the summer vacation. What the boys were going to do after the encampment came to an end, had not yet been decided.
Sunday was passed quietly by the Rover boys and their chums. Religious services were held in the open air, and were attended by nearly all of the cadets. In the afternoon Fred and Jack took a walk, accompanied by Gif and Spouter, the twins remaining behind to write some letters.
The walk took the cadets to the foot of the cliff nearest to their camp, and in rounding this close to the water front they made a somewhat interesting discovery. They came to quite an opening among the rocks, and, going inside, found themselves in a regular cavern, ten feet high in some places and half again as broad. In the rear was a smaller opening, leading downward and filled at the bay level with water.
“Who would think there would be a cave like this around here!” remarked Jack.
“Good place to come to in case of a storm,” said Spouter. “A fellow could play Robinson Crusoe if he wanted to.”
By the aid of some matches the cadets examined the cavern, but found nothing in it of value. At some time in the past birds had nested there, but that was all. They were just ready to leave when Jack suddenly put up his hand.
“Listen!” he said. “Am I mistaken, or do I hear something?”
All did as he commanded, and from a great distance a faint tapping reached their ears. Then came a series of muffled explosions and a clanking as of chains.
“That’s something like the noise Randy said he heard when he was on sentry duty,” remarked Fred. “Don’t you remember how worked up he was over it?”