"Well, you four little Bunkers that are still awake had better go to bed so you'll be able to eat breakfast as well as guess riddles to-morrow,"

laughed Mother Bunker. "Come on! To bed with you! Mun Bun and Margy fell asleep long ago."

So off to bed they went, not even dreaming about the strange things that were to happen the next day.

About an hour after the six little Bunkers were in Slumberland, Captain Roy, who had been over to the bunk-house to talk with some of the cowboys, came hurrying in where Uncle Fred was.

"Anything the matter?" asked the ranchman.

"Yes," answered the captain. "More of our cattle have been taken!"

CHAPTER XXV

THE SECRET OF THE SPRING

"More cattle taken?" cried Uncle Fred. "When did that happen?"

"Just a little while ago," answered Captain Roy. "One of the cowboys just rode in with the news."

"Well, this is too bad!" cried Uncle Fred.

"I'll tell you what let's do," said Daddy Bunker. "It isn't very late yet. Let's go out and look at the spring."

"What for?" asked his wife.

"Well," answered the father of the six little Bunkers, "I want to see if the water has run out of it this time. Perhaps it hasn't, and, if so, it would mean that the taking away of Uncle Fred's cattle didn't have anything to do with the mysterious spring."

"Well, it will do no harm to take a look," said the ranchman. "Come along, Captain Roy. We'll see what it all means."

Taking lanterns with them, they went out in the dark night to look at the spring.

"It's just the same," called Daddy Bunker, when he had taken a look.

"The water is almost out of it."

"Then we must start, the first thing in the morning, digging at the place where the boys made their well," declared Uncle Fred. "I must get at the bottom of the secret of my spring."

"And I'd like to find out who it is that's taking our cattle!" exclaimed Captain Roy. "I think, in the morning, I'll take some of the cowboys and have a big hunt. This business must stop. Pretty soon we won't have any ranch left at Three Star. I'm going to find the men that are taking the cattle!"

When the six little Bunkers awoke the next morning, there was so much going on at Three Star Ranch that they did not know what to make of it.

Cowboys were riding to and fro, Uncle Fred and Daddy Bunker were dressed in old clothes, Captain Roy had a gun slung over his shoulder, and many horses were standing outside the corral, saddled and bridled.

"Are we going on a picnic?" asked Vi. "Is there going to be a parade? Is the circus coming? What makes so many horses? Is there going to be a prairie fire?"

"Well, I guess you've asked enough questions for a while, little girl!"

laughed her mother. "Come and get your breakfast now."

"But what's going on?" insisted Violet.

"Two things," her father told her. "Your uncle and I are going to dig deeper in the well Russ and Laddie started, to see what makes the gurgling sound of water under the earth at the bottom of it. And Captain Roy is going to try to find the men who took Uncle Fred's cattle last night."

"Oh, can't we help?" asked Laddie.

"You may come and watch us dig your well deeper," his father told him.

"But it would not be safe for little boys to go hunting men who take cattle."

Just as Captain Roy and a lot of cowboys were about to ride off over the plain and Daddy Bunker and Uncle Fred were going to dig at the boys'

well, Mrs. Bunker came out of the bunk-house. She had gone to see if the man with the broken leg needed anything.

"He wants to see you," she said to Uncle Fred. "He says he can tell you a secret."

"Tell me a secret!" exclaimed the ranchman. "Does he mean about the mysterious spring, or the stolen cattle?"

"He didn't say," answered Mrs. Bunker. "But he wants you to come to see him."

So Uncle Fred went. He stayed a long while in the room where Sam Thurston, the strange cowboy, had been put to bed after his broken leg was set, and when Uncle Fred came out he was much excited.

"Wait a minute, Captain Roy!" he called to his partner. "I can tell you where to look for the cattle that were taken last night."

"Where?" asked the former army man, pausing at the head of his band of cowboys.

"Over in the gully by the creek. They're hidden there."

"Who told you so?"

"Thurston, the strange cowboy. And he has also told me the secret of the spring, so we won't have to do any digging, Daddy Bunker."

"We won't? Why not?" asked the children's father in surprise.

"Because the cowboy says the reason the water stops coming in at certain times is because of something that happens back in the hills, where my spring starts, in a brook that runs under ground after its first beginning. Back in the hills the men, who have been taking the cattle, turn the water into another stream. That's why it doesn't run into mine, and that's why my spring dries up."

"But why do the men shut off our spring water?" asked Captain Roy.

"They do it to make a wet place so they can drive my cattle across it, and no hoof marks are left to tell which way the animals have gone.

Then, when the cattle are safely away, the waters are let run down where they always flow, and they come into my spring again. The taking of the cattle and the drying up of my spring are all done by the same band of men. That's why, whenever any cattle were taken, the spring dried up.

One went with the other."

"How did Sam Thurston know all this?" asked Daddy Bunker.

"This cowboy with the broken leg used to be one of the band of men who took my cattle," went on Uncle Fred. "He just told me. He was on his way to see about taking more of my steers when his horse threw him at the bridge. That's why he didn't want to come to Three Star Ranch--because he had treated us so meanly.

"But when he saw how good we were to him he made up his mind not to be bad any more and to tell about the men. He knows where they hide the cattle after they steal them, and he says if we go there now we can get back the steers, and also catch the men who took them. And after this the spring won't go dry any more."

"Well, well!" exclaimed the children's father. "And to think that two of the six little Bunkers, by finding the cowboy with the broken leg, should help solve the spring mystery!"

"It is extraordinary!" exclaimed Uncle Fred. "But I knew as soon as I saw the little Bunkers in the attic that day I walked into your house, that they could do something. And they have. Now, Captain Roy, you and the cowboys ride on and see if you can get back our cattle."