There was but one reasonable supposition, and that was that one or more of the Rackbirds, who had been away from their camp at the time when their fellow-miscreants were swept away by the flood, had come back, and in searching for their comrades, or some traces of them, had made their way to the caves.  It was quite possible, and further it was quite probable, that the man or men who had found that mound might still be here or in the neighborhood.  As soon as this idea came into the mind of the captain, he prepared for action.  This was a question which must be resolved if he could do it, and without loss of time.  Lighting his lantern,—­for in that black darkness it was impossible for him to find his way without it, although it might make him a mark for some concealed foe,—­the captain quickly made his way out of the lake cavern, and, leaving his lantern near the little wall, he proceeded, with a loaded pistol in his hand, to make an examination of the caves which he and his party had occupied.

He had already looked into the first compartment, but stopping at the pallet which lay almost at the passage of the doorway, he stood and regarded it.  Then he stepped over it, and looked around the little room.  The pallet of blankets and rugs which Ralph had used was not there.  Then the captain stepped into the next room, and, to his surprise, he found this as bare of everything as if it had never been used as a sleeping-apartment.  He now hurried back to the first room, and examined the pallet, which, when he had first been looking at it, he had thought to be somewhat different from what it had been when he had used it.  He now found that it was composed of all the rugs and blankets which had previously made up the beds of all the party.  The captain ground his teeth.

“There can be no doubt of it,” he said.  “Some one has been here since they left, and has slept in these caves.”

At this moment he remembered the innermost cave, the large compartment which was roofless, and which, in his excitement, he had forgotten.  Perhaps the man who slept on the pallet was in there at this minute.  How reckless he had been!  To what danger he had exposed himself!  With his pistol cocked, the captain advanced cautiously toward the innermost compartment.  Putting his head in at the doorway, he glanced up, down, and around.  He called out, “Who’s here?” and then he entered, and looked around, and behind each of the massive pieces of rock with which the floor was strewn.  No one answered, and he saw no one.  But he saw something which made him stare.

On the ground, at one side of the entrance to this compartment, were five or six pieces of rock about a foot high, placed in a small circle so that their tops came near enough together to support a tin kettle which was resting upon them.  Under the kettle, in the centre of the rocks, was a pile of burnt leaves and sticks.