a detour, coming
up on the opposite side of the growth, and at a distance of three
hundred yards. He was on a slight hill, and could look directly down
upon the spot the Confederates, with the extra horses, had occupied. As
Captain Ripley had said, the enemy was nowhere in sight.

The men looked at Deck, and it must be confessed the major felt
uncomfortable, for he had been certain that something would turn up when
a better view of the ground back of the brush was obtained.

"We will advance,--but do so cautiously," said the major, and drew his
pistol. Hardly two hundred feet had been covered when he made a
discovery. The brush overhung a small, rocky brook, probably three feet
deep in the centre. But where the water came from and where it went to
was another question. Certainly, in making the detour, he and his men
had crossed no such watercourse.

"It must come either from a powerful spring or from underground," he
reasoned. "Forward!" he shouted. "That running stream must solve the
mystery."

The brook was soon gained, and found to flow to the southwestward. A
detail was sent up the stream, and soon came back reporting that there
were several small springs there, but the larger portion of the water
came from a flow out of the side of a small hill.

Major Truman now reported that the Riverlawns had surrounded the entire
territory, and feeling certain he had the enemy secure, Deck continued
his investigation. Several cavalrymen were sent down the centre of the
brook, while he kept abreast of them beyond the brush.

Almost the end of the wood was gained, when the cavalrymen shouted out
that they had reached a small waterfall, and could go no further.
Pressing over the rocky ground, Deck gained the waterfall, to find at
its bottom a well-hole in the almost solid rock, some fifty or sixty
feet in diameter. At the bottom was a pool, partly covered with dead
brush and decayed tree trunks, and the water ran off in a large opening
to one side of the well-hole.

"Here are horses' hoof-prints, Major," said one of the men. "I shouldn't
wonder if there is a winding path leading down to that 'air pool. But if
the rebs went down there, what became of 'em?"

"There may be a cave there," answered Deck. "These underground
watercourses often flow through caves around where I live, not far from
the Mammoth Cave."

"To be sure, Major. Shall we go down?"

"Yes, but be on your guard."

The winding path was soon traced out, a