“Strange!” whispered Charley, as Dick signed the register. “There could hardly be two with such a name.”

Dick had told Charley all about his adventure, of course.

“I don’t see how it can be the same man,” he said, “but we’ll soon find out. Do you know that gentleman?” he asked the clerk, pointing to the name.

“Yes, I know him,” was the reply. “He came in by the westbound train this morning. He used to live here. Why do you ask?”

“Because I met him in Washington only a few days ago. Is he in the hotel now?”

“No,” replied the clerk. “He bought a horse and went off up into the mountains. He’s a mining prospector. If you should happen to meet him I advise you strongly to give him the cold shoulder. He’s a bad lot.”

“Is he crazy?” asked Dick.

“Not he!” exclaimed the clerk. “He’s a big liar, though, and a thief from way back, but he’s well educated and can talk almost as well as Doctor Dan.”

“What about Doctor Dan?” asked Charley. “Is he all right?”

“Yes, you can bank on him every time, even if he is an Indian. Queer feller, isn’t he? They say he’s got a lot of education, but an Injun’s an Injun wherever you strike him, that’s sure.”

Having delivered himself of this sentiment the clerk wrote the room number after the boys’ names and Dick and Charley went in to dinner, which was much better than they expected to find.

At one o’clock precisely the start was made, Doctor Dan appearing on the scene with the horses and mules.

All the rest of the afternoon the ride continued.

Their way led over a barren plain overgrown with sage brush and strewn with the white alkali of the country.

High mountains rose in the far distance. Doctor Dan informed the boys that they skirted the edge of the Bad Lands.

When night came on a halt was made and Doctor Dan put up the tents in the most expert manner, hobbling the horses and cooking a splendid supper of antelope steak and a sort of cornbread, which he rolled out on a flat stone and cooked in round balls among the hot ashes.

After supper the boys rolled themselves up in their blankets and slept comfortably until morning, Doctor Dan going on guard.

He informed the boys that he was accustomed to going three or four days at a stretch without sleep and that they would not be called upon to mount guard at night until they reached the lake and probably not then unless they found some special cause for alarm.

The second day’s journey resembled the first too closely to need description. When they went into camp that night they could see beyond them a stretch of country which appeared to be one mass of great sand hills which rose in every direction.

Doctor Dan informed them that this was the beginning of the Bad Lands.

“Those sand hills run away over into South Dakota for more than a hundred miles,” he declared. “It’s a terrible country. Not a drop of water anywhere. There is nothing like it in the whole world.”

Dick and Charley were all anxiety to see it and within a very short time after they started out next morning their wish was gratified, for they found themselves in the midst of the sand hills steadily advancing toward an isolated peak, which Doctor Dan informed them was their destination.

It was a fearful country surely. As far as the eye could reach the sand hills rose all around them, with not a tree nor a blade of grass visible anywhere.

Later in the day they began to ascend and at last came out upon a broad table land, a mere desert of yellow sand, broken by great rifts called barrancas in every direction. It required an artist to work around these breaks, but Doctor Dan seemed to be perfectly acquainted with the trail, although he declared that he had never visited this part of the Bad Lands, excepting on his previous trip.

The mountain was now steadily drawing nearer, and by four o’clock they reached its base without having seen the slightest sign of life of any kind since they entered the Bad Lands.

“Now, then, where does the lake lie?” asked Dick, looking up at the towering cliffs of reddish, disintegrated stone which rose above them.

“It’s in that direction, about a thousand feet up,” replied Doctor Dan, pointing.

“Can we ride up?”

“Oh, yes. There’s an easy trail. It’s almost like a road, but it winds about a good deal.”

“Then we go right on and camp there?”

“Just as you say, sir.”

“I say yes, by all means, providing it is a good place for our camp.”

“It is quite as good as it is here. Better, in fact, for the lake lies in a sort of natural basin and if we should happen to get a snowstorm, which we may, we would be protected.”

“We will go right on, then,” said Charley. “Hadn’t we better, Dick?”

“Decidedly,” replied Dick. “We can get our permanent camp all fixed up before dark.”

The ascent then began. As they passed up the mountainside with no trees to obstruct their view, the boys were amazed at the wonderful panorama displayed.

It was as if they were looking down upon a sea of sand, and it was easy to imagine it the bed of some old, vanished ocean, as scientists tell us the Bad Lands actually are.

For half an hour the horses toiled up the steep slope, first to the right, then to the left, but always rising until at last they came suddenly out upon a level plain, entirely surrounded by towering cliffs, except for the narrow break through which they entered.

“The crater of an old volcano!” cried Dick. “That’s what this place is sure.”

“So I have been informed,” replied Doctor Dan, with his usual gravity.

“Where’s the lake?” asked Charley.

“Just around that bend in the cliffs,” was the reply. “This sink is double, as you may say. The wall runs pretty near through the middle of it. One half is dry and the lake fills the other half. We shall see it in a minute now.”

They rode on and soon turned the corner of the dividing cliff.

A broad stretch of water now lay before them. The lake was many times longer than the dry half of the old crater.

Its surface was perfectly placid and the water seemed to give out a strange, sulphurous odor. The shores were broken by projecting points of rocks, which cut up the lake into many small coves.

“Now, where’s your Plesiosaurus?” exclaimed Charley. “Let him show himself. He’s got an audience that will appreciate him, you bet.”

“It was right over there abreast that little island that I first saw him,” said Doctor Dan, gravely. “His body reached almost to that point of rocks on the opposite shore. I hope you don’t think it is all a fake, boys, but I suppose you will never believe it until you see for yourselves.”

“That’s what we are here for,” replied Dick, “and it is no reflection on you, doctor, if we find it hard work to believe what we have not seen, but where do we make our camp?”

Doctor Dan pointed out the spot where he and Ike Izard had camped and there, sure enough, the boys found traces of a fire and other things which seemed to prove his story true.

The horses were now hobbled and the tents pitched.

Dr. Dan cooked supper in his usual fine style and everything was arranged for the night.

When the supper was over, as it was not yet dark, Dick proposed a walk, and all three, shouldering their rifles, for there was no telling what might happen, started along the lake shore, winding in and out around the projecting cliffs until they had gone at least a mile.

It was now getting toward dusk and Dick, in spite of his hopes, began to abandon all idea of seeing anything of the monster of the lake that day.

“I suppose we might wait around here for days and not see him,” he said. “Wonder how long a Plesiosaurus can stay down under the water, anyhow?”

“Is it known?” asked Doctor Dan.

“Certainly not, since only their bones have been found,” replied Charley, “but it must be an air breathing animal or it couldn’t have swum round with its head above the water the way you saw it.”

“If that’s the case he must come up every little while,” said Dick.

“I don’t know,” answered Doctor Dan. “We stayed round here two days after we saw the thing, but it never showed itself again. I’ve got a theory about that, but I don’t suppose you young men care to hear my views.”

“Indeed we do,” cried Dick. “Out with it, doctor.”

“Why,” replied the Indian, “my idea is that this lake connects with another, which is hidden underground, and that the Plesiosaurus makes its home down there and so gets all the air it needs without coming to the surface at all.”

“And a very plausible theory it is,” said Dick. “I was thinking——”

Right here Dick was interrupted by a wild cry from Charley.

“Look there! Look there!” he shouted, pointing to the rocks right in front of them, which concealed the entrance to another cove.

Dick and Dr. Dan grasped their rifles and started back in terror.

Right in front of them, not ten feet away, a huge, shiny head, long and flat, with an enormous mouth filled with horrible teeth and two great, glittering eyes set on the sides, projected over the rocks.

“The monster!” shouted Dick, and instantly the head darted forward, followed by a long, sinewy neck as big round as a man’s body.

The horrid jaws opened and closed with a vicious snap and a frightful bellow rang out among the rocks.