“If we get it safely put away in our cave,” chuckled Mark as he hurried on, “we may be pretty sure that all danger will be over.”

“I thought I’d die,” remarked one of the others, “when I found that Bull had left it lying in Fort Clinton where anybody might find it. You know when we fellows put the clothes on him so’s to get him arrested for a joke, he must have gotten back to camp pretty late and just had time to peel before reveille in the morning. Bull Harris ought to have been more careful than to leave it there.”

“Doggone his boots!” growled Texas. “Them ole yearlin’s never did have any sense!”

The “den,” toward which the Seven were hurrying, lay about two miles away in the woods. A small hole in the side of a cliff was its only known entrance, discovered by the parson while “geologizin’.” That den was a dark and mysterious place, the source of no end of strange adventures.

As old readers know, it had originally belonged to a gang of counterfeiters some fifty years ago. They had been entrapped in a secret corner of it and accidentally suffocated. Their skeletons had remained there to horrify the plebes, when first they had the temerity to enter the place.

A few days later a treasure had been found there. It proved to be counterfeit in the end, but not until it had given rise to considerable excitement. Altogether, that den was a delicious place in which to spend a holiday afternoon. You never could tell what might happen.

“We haven’t been near it for a week or two,” observed Mark. “I’ve had so much to do I haven’t even had time to think of it. I wonder if anything has happened meanwhile.”

“Perhaps the skeletons have come to life,” hinted Dewey, whereat poor Indian shivered and cried “Oo!”

By this time they had reached their destination. It does not need much describing. There was a tall surface of rock facing the river, which was only a short distance away. The entrance to the cave was completely hidden with a growth of bushes and there was nothing but a few faint footprints to indicate that anybody ever came near the place.

Such was the “den” from the outside. The Seven were climbing up and crawling in head first, so we shall follow them and take a look inside.