"Did you hear that?" asked Russ of Laddie, as they stared about them.

"Course I heard it."

"What did it sound like?"

"Like the ghost at Great Hedge," said Laddie.

"Yes," agreed Russ, "that's what it did sound like—a sort of groan. But there can't be any ghost here."

"Course not. But what was it?"

Laddie and Russ looked across the bridge, but could see no one on the other side.

Then the groan sounded again, quite near them, and the voice again called:

"Water! Water!"

"Somebody wants a drink," said Laddie.

"But who is it?" asked Russ. "I don't see anybody."

"It sounds like a man," replied Laddie.

"Maybe it's an Indian," said Russ. "But I don't guess Indians would talk as plain as that. Maybe it's one of Uncle Fred's cowboys, and he fell off his horse and is hurt."

"Oh, maybe 'tis!" exclaimed Laddie. "But if it's a strange cowboy we must ride right home. Mother said so."

"We got to get him a drink first," decided Russ. "You always have to do that. You have to do that even to an enemy, 'cause we learned that in Sunday-school. Let's see if we can find who 'tis wants a drink."

Suddenly the voice called again, so loudly and so close to them that Russ and Laddie both jumped when they heard it.

"Whoever you are, please get me some water!" said the voice. "I'm a cowboy and I've fallen off my horse and broken my leg."

"Where—where are you?" asked Russ, looking about.

"In the tall grass, right at the end of the bridge. I can see you boys, but you can't see me because I'm hidden in the grass. I was going to ride over the bridge, but my pony slipped and threw me and I've been here some time with a broken leg. Get me a drink if you can."

Russ and Laddie looked at each other. Then they looked toward the end of the bridge, where the voice sounded, and they saw the long grass moving.

"He must be in there," said Laddie, pointing.

"He is," answered Russ. "Here, you hold Star and I'll get him a drink," and Russ slipped off his pony, taking off the cap he wore. Russ had an idea he could carry some water to the cowboy in the cap, and in this he was right.

Going down to the edge of the creek, at one side of the bridge, Russ dented in the outside top of his cap, and filled it with water.

Then, carrying the cap as carefully as he could, Russ made his way to where the cowboy had called from. The little boy found the injured man lying in the tall grass.

"Ah! That's good!" exclaimed the cowboy, as he drank the water. "Now if you could catch my horse for me maybe I could get up on him, and ride him to where I belong. Do you see my horse anywhere?"

Russ looked all about. At first he saw nothing, but, as he gazed across the bridge he saw, on the other side of the creek, a big horse eating grass.

"I see him!" said Russ to the cowboy. "He's over the bridge."

"Is he? That's good. Then he didn't go very far away, after all. Now, look here, you seem to be a pretty smart boy," and the cowboy spoke in a stronger voice, now that he had had a drink of water. "Do you want to help me?"

"Yes," said Russ, "I'd like to help you. My mother says we must help everybody, and give them a drink of cold water, even our enemies, and I know you're not an enemy."

"I don't know about that," said the cowboy with a queer laugh, and he turned his head away and seemed to be looking at his horse, which was on the other side of the bridge, eating grass.

"No, you're not an enemy," went on Russ. "An enemy is a bad man, and you're not that."

"I wouldn't be so sure on that point, either," returned the cowboy. "But I won't hurt you, that's certain. Now look here, boy——"

"My name is Russ Bunker," interrupted the lad.

"Well, Russ, do you think you could go across the bridge and get my horse for me? If I had him I could ride away, now that I feel better after having had a drink. Will you cross the bridge and get my horse for me?"

"No," said Russ slowly, "I couldn't do that."

"Why not? The horse won't hurt you. He's so tame you could walk right up to him, and get hold of the reins. He won't run the way some horses do. You know something about horses or you wouldn't be riding one. Why won't you get mine?"

"'Cause Mother said I wasn't to cross the bridge alone," answered Russ. "Me or Laddie—we can't go across the bridge alone."

"Oh," said the cowboy. "But then your mother didn't know you were going to meet a sick man—one that couldn't walk. She'd let you cross the bridge if she was here."

"But she isn't here," said Russ. "I know what I can do, though! I can ride back and ask her if Laddie and I can go across the bridge for your horse. I'll do it!"

"No! Wait! Hold on a minute!" cried the cowboy. "I don't want you to do that. I don't want you to ride and tell any one I'm here. I'd rather you'd get my horse for me yourself. Just ride your horse across the bridge and get mine."

"I haven't a horse. I have one of Uncle Fred's ponies," said Russ. "And my brother Laddie's got a pony, too. But I can't go across the bridge. Mother said I wasn't to. But I'll ride to Three Star Ranch——"

"Are you from Three Star Ranch?" asked the cowboy quickly.

"Yes," answered Russ.

"Oh!" and the cowboy seemed much surprised. "Well, I guess I'd better get my own horse then," he said. "I guess no one from Three Star Ranch would want to help me if they knew what I'd done. Ride along, boy—Russ you said your name was, didn't you? Ride along, and I'll see if I can't crawl over and get my own horse."

Russ did not know what to do. He wanted to help the cowboy, who seemed in much pain, but the little boy was not going to cross the bridge when his mother had told him not to.

"Hey!" called Laddie. "Come on, Russ. I'm tired of holding your pony."

"All right," said Russ. "I'm coming. We have to ride back and ask Mother if we can cross the bridge to catch that horse!" and he pointed to the cowboy's animal, still cropping grass on the other side of the creek.

"No, don't bother about me," said the man in the grass. "I'll get my own horse. Always be a good boy and mind your mother. Then you won't get into trouble. I wish I had minded mine. Maybe I wouldn't be here now. Ride on home, but don't say anything about me."

Russ turned back to join Laddie. As he did so he saw the cowboy try to rise up and walk. But the man, as soon as he put one leg to the ground, uttered a loud cry and fell back. Then he lay very still and quiet.

"What's the matter with him?" asked Laddie, in a low voice.

"I don't know," answered Russ. "But I guess we'd better ride back and tell Daddy or Uncle Fred. They'll know what to do. We can't cross the bridge, but we can go for help. Come on!"

Russ got on his pony again, and he and Laddie rode away as fast as they could, leaving the cowboy very still and quiet, lying in the long grass at the end of the bridge.

Meanwhile something was going on back at the Three Star Ranch house. Uncle Fred and Daddy Bunker, who had been out riding on the plains, came galloping back.

"Where are Russ and Laddie?" asked their father of his wife.

"They went for a ride down by the creek," she answered. "They said they'd go only as far as the bridge. But they've been gone a long while, and I wish you'd ride after them and bring them back."

"I will," said Mr. Bunker. "Want to come for a ride, Rose?"

"Yes, Daddy."

"Well, I'll get your pony out of the corral, and saddle him for you. Then we'll ride and get Russ and Laddie."

A little later Rose and her father started out on their ride. As they passed near the queer spring, which, for the last day or so had not emptied itself of water, Daddy Bunker saw quite a hole in the ground.

"What's that?" he asked Rose.

"Oh, it's where Russ and Laddie started to make a well," she answered. "But I guess they didn't find any water."

Daddy Bunker got off his horse to take a look. He bent over the well the boys had dug, and stooped close down to it. As he did so a queer look came over his face.

"I wonder if this can be the place?" he said to himself.

"What is it?" asked Rose.

"I don't know," her father answered. "But it sounds to me like running water down near where Russ and Laddie have been digging. If it is, it may mean we can find out the secret of Uncle Fred's spring. I guess I'd better go and tell him. It won't take long, and then we can all ride on and get Russ and Laddie, if they aren't back by then.

"Yes, I shouldn't be surprised but what those two boys had started to solve the riddle of the spring. I must tell Uncle Fred!"