The professor's hand trembled with excitement as he scratched the surface of the rock, tapped the face of the wall for a possible hollow sound, then called on Bet to bring him a pick.

He dug at the base of the wall, but soon came to solid rock.

"There's nothing there!" he exclaimed. "But this is interesting." The desert weeds had grown over all the crevices in the rock, and when the professor had carefully scraped them away, he found what he had hoped for; a small opening. Behind that wall there was a tunnel. As he looked into the darkness, a rattlesnake glided through the hole, and the old man sprang back just in time to save himself.

"That was a close shave!" Wiping his forehead with his handkerchief, Professor Gillette sat down on the rock to decide what the next step would be.

"Guess we'd better call it a day. We are all tired out. We can just get back in time for dinner," said Enid. "And Dad said you were to come home with us, Professor."

"I'd like to consult with the judge," said the old man. "He can give us valuable advice I'm sure." He wouldn't for the world acknowledge that the hot dinner, already prepared, tempted him to accept the invitation.

The girls turned away from the wall, unwillingly. They now felt sure that they were leaving a treasure behind them. And tomorrow seemed so far away!

Bet and Enid helped Joy to hobble along to the edge of the cliff, and Kit hastened down the incline to where they had left the horses near the stream.

"I'll bring Dolly up, that is if she'll climb, the lazy thing!" called Kit as she disappeared. By this time Joy's foot was badly swollen and was giving her acute pain.

Before leaving the wall, the professor had concealed the opening that he had found. As he turned to go he picked up a bit of the rock that he had pried loose.

It was this rock that kept the secret of the tunnel from Ramon Salazar, hidden in the brush of the hill opposite, where he had been set to spy on the girls by Kie Wicks.

He had become rather weary of his job until he saw the professor examining the wall of the cliff, then he braced himself up expectantly, but relaxed again when he saw the old man looking closely at a rock in his hand, which he carried away with him.

"He's found a colored stone that he likes," Ramon said to himself with a sneer of contempt at the professor who was always treasuring the brightly colored mineral specimens.

And it was this report that he carried to Kie Wicks: "They just fooled around, had a picnic, and climbed the hill above the claims. I don't believe they even know you jumped them."

"You mean you jumped their claims," corrected Kie Wicks.

Ramon laughed and slapped his leg. "That's a good one, yes, I jumped their claims."

"And you'd better get busy with the assessment work, too," advised Kie.

"Who pays me for that?" demanded the cross-eyed Mexican.

"There you go again! Always wanting money! I find you some good claims and a chance, maybe, to sell out at a big price in the future, and you want pay for doing the assessment work. You're an ungrateful cur!"

"Then I won't do the work. No pay, no work!"

But even as he spoke, Ramon knew that he would do whatever Kie Wicks asked him to do. The habit of obedience to this man was too strong in him. He had been a tool for this unscrupulous rogue for more than ten years. Just why, he could not have told, for Kie Wicks was not a generous master and the Mexican got little enough for his work. Rarely ever did he get any cash out of the storekeeper, and the supplies that Kie doled out were given grudgingly. Yet the man always returned, after promising himself many times that he was through.

Kie had given him a small shack in the canyon, that had once been used by some friends of his for a summer vacation, and it was this home that sheltered his wife and eight children, which kept the Mexican faithful to Kie.

Ramon had a bad name in the hills. He had tried his hand at every kind of rascality. Cattle had disappeared, horses rustled and Ramon was suspected of knowing more about them than he should. Yet it was Kie Wicks behind him, threatening and driving him on, that made Ramon the character he was.

And while Ramon refused, at first, to go on with the assessment work on the stolen claims, he knew that he would do it in the end, and that Kie would also give him supplies while he was working on the job.

Ramon did not like to meet the girls and perhaps Judge Breckenridge. The professor, he felt, was harmless, a silly old man who roamed through the hills, but the impressive looking judge was a different matter.

Yet the next morning when the professor arrived with the girls, Ramon was digging away at the farthest claim, and did not even look up.

"Guilty conscience!" whispered Bet to the professor.

"He complicates matters considerably," frowned the old man. "I hardly know how we are going to proceed, if he stays around here."

"With Ramon watching, the only thing to do was to go on with the drilling on the Orphan Annie claim. Bet fumed and fussed, scolding anyone who came near her. She insisted on being the professor's helper, holding the drill in place with the strong wire while he hammered. This gave her an audience and was an outlet for her anger against Kie Wicks and his Mexican hanger-on.

"Take it easy, child. There's lots of time to find that treasure—that is if there is one. We don't need it right away, you know," soothed the professor.

But it took Bet a long time to regain her poise. The other girls had recovered from their disappointment and were trying to make friends with the Mexican before Bet would even smile.

"I do wish we could tell which of us he's talking to. His eyes are so crooked they overlap," whispered Enid to Bet. The Mexican did not want to make friends with the girls. He answered a few words to their questions then went moodily on with his work. But not for long. Without a master over him, the man grew lazy and before the morning was far advanced he had disappeared in the canyon.

"I thought he'd get tired of it," smiled Kit. "A Mexican miner has to have someone to keep him on the job. And I don't believe that Kie Wicks will spend much time over here."

Ramon was no sooner out of sight than the professor dropped the drill and they rushed for the wall to begin digging there. They had just started to work when Judge Breckenridge rode up.

"Let's have a look at that treasure tunnel, Professor," greeted the
Judge with a laugh. "How much bullion have you found?"

"Not any yet, but who knows?" returned the old man, his eyes shining with excitement.

"Stranger things have happened!" The Judge followed the girls and looked at the wall. "Well, well," he exclaimed, "this certainly looks interesting."

The professor had already begun to pick away the crumbling rock at the small opening, and found that they had hit upon the spot where the mouth of the tunnel had been filled up. After half an hour's work he had opened it sufficiently to look in. Using a flashlight, he could see that the tunnel was very shallow, another wall confronted him and this appeared to be the solid rock of the mountain.

He was about to give up when he noticed a peculiar stone on the floor of the tunnel, or what appeared to be a stone. With the pick he dragged it forward and was able to reach it. Drawing it forth, he stood before the Judge with glowing face.

"See this!" he exclaimed excitedly. "This comes up to any story of buried treasure that I've ever read in my life." He displayed his find, a tiny disc of copper and on it were engraved strange figures and signs. They had no meaning to the group of people that stood about the tunnel. But that little copper plate was telling a story, of that there could be no doubt.

"What do you think of it?" the professor gasped in a hoarse whisper. The old man was almost too excited to speak. He made several attempts then gave up, but he held the disc as if it were a jewel.

"Let's sit down away over here and have a look at it," the Judge suggested. "And if anyone is spying on us, he'll not be apt to suspect anything."

Judge Breckenridge examined the disc carefully then spoke.

"Now there is a possibility—a slight one, we'll say, that there is a treasure in that vault somewhere. Do you think your friend Ramon is suspicious?"

"It's hard to say," Kit burst out. "Kie Wicks may be watching us this minute from over the hill across the canyon."

"We will want to carry on the work as quietly as possible, but if Kie hears about a treasure, we'll not have a minute's peace," said the Judge, rising and surveying the ground. "The first thing we ought to do," he continued, "is to stake out a claim covering this wall. Then we'll own it."

"Yes, and have Kie Jump that claim, if he is watching us." Bet shrugged her boyish shoulders.

"We'll get ahead of him on that. We'll stake the claim and I'll send a man over to record it first thing in the morning, and tonight we'll have a watchman—two in fact. We'll not leave the tunnel unguarded for a minute until we find out what it contains."

"Oh, please, Judge, let us guard it!" cried Bet.

"No!" There was a harsh, decided ring in the Judge's voice and the girls did not urge him further. That "no" meant exactly that.

"I think it might be a good idea for me to go back to the ranch and get Tommy and some of the boys to move the professor's tent up here and Tommy and Seedy Saunders might stay for a few nights to guard your claims. You'll have all the excitement there is in it, even if there is no treasure."

Bet flared up at once. "We're not so silly as to want excitement and nothing else. We want the treasure now that we have started out to find one. Nothing else will do."

The Judge laughed as he mounted his horse and rode down the trail.

But when he returned to the ranch and informed the boys what he wanted, he was met with roars of laughter.

"You want us to guard a buried treasure! That's a good one!" said
Seedy Saunders, the old cowboy who was now staying with Judge
Breckenridge. "Let Tommy do it! He has a treasure map in his shack
that he paid five dollars for. He'd love to do it!"

However, when the cowboys heard how much it meant to the girls to have the tunnel guarded against Kie Wicks, they entered into the spirit of it, and even though they laughed and joked, they carried out the Judge's instructions.

They moved all the professor's belongings over the mountain, and took another tent and cots for themselves.

"There just naturally has to be two of us," insisted Seedy. "We'd be scared stiff to sleep alone there, even with the professor."

"Which are you scared of?" laughed Tommy Sharpe. "Kie Wicks or the ghost of the Indian Chief's daughter?"

"Both," returned Seedy pretending to shake with fright. "But I'm mostly scared of that there ghost that walks."

The boys were hilarious as they unpacked their stuff at the Orphan
Annie claim.

"By rights we ought to camp in the canyon, we'll have to pack all the water up the hill," suggested Tommy.

"You'll camp right at the mouth of that tunnel, boy!" insisted Enid, and there was something of Tilly the Waif in her command. Tommy looked up at her quickly, then burst into laughter.

"Yes'm," he said meekly with a twinkle in his eye. "I obey!"

They had the tents pitched and the girls were arranging the beds and making them cozy when Judge Breckenridge returned, with a boy driving a burro loaded with provisions.

In his hand he held something white which he waved as he came up the mountain?

"It's a letter!" exclaimed Bet. "I hope it's from my Dad. I haven't had a letter for a week."

"It's a letter for me," announced the Judge, "but it may contain news that will please you. The boys will arrive this week. Phil and Bob are going to join us."

A shout went up and echoed through the hills.

Tommy gave an Indian war-whoop and the girls danced about, hugging each other in their joy.

"Won't it be good to see them!" exclaimed Bet.

"Is Paul coming with them?" asked Enid. "I'm homesick for my brother," she murmured with a happy sigh.

"Yes, the three boys will come together by airplane to Phoenix," said the Judge.

"By airplane!" echoed Bet Baxter. "If they don't let me go up with them, I'll never speak to them again, never. I want to fly!"

The hunting for treasure took second place now. The coming of their friends was more important than anything else.

"You know," said Kit solemnly, "we shouldn't get so fond of those boys.
We'll spoil them."

"I've never seen any spoiling!" Billy Patten had helped Judge Breckenridge bring over the supplies, and now confronted Kit. "Don't pretend you're soft-hearted, for you're not."

Kit laughed at her teasing brother and with a wave of her hand pushed him aside. "Children should be seen and not heard," she said.

"What did Joy say when you told her that Bob was coming?" asked Bet.

"She shed a few tears; perhaps she was afraid she would miss all the fun with her sprained ankle."

"She's in luck if she only knew it," laughed Enid. "A girl with a sprained ankle will just appeal to the sympathy of those boys. Joy will be the center of the stage."

"And won't she love it?" chuckled Kit.

With many final instructions to the boys to guard the tunnel, the girls mounted their horses and hurried toward home, their faces glowing with joy.

From the mountain opposite, where Ramon had watched the previous day, Kie Wicks was on guard. He saw the preparations for camping at the claims and wondered what it was all about.

His eyes narrowed to pin-points when he saw the professor examining the wall of the cliff.

"What's he got there?" he muttered to himself. "But he can't put anything over on me. If I could get my hands on Ramon, I'd teach him to do as I tell him. If he had stuck around, I'd know what all this fuss is about."

But that was all that Kie was to know for some days. He watched by the hour, he questioned every man, woman and child he met, but the professor and his men were not talking. The location work on the Orphan Annie claim and the digging of a tunnel seemed to be their only interest.

Kie noticed that a monument had been built to cover the claim where the tunnel was being driven and smiled to himself. "These city fellows think they've got a mine with a couple of claims. They've got a lot to learn!"

The secret had to come out, of course. And when Kie Wicks heard it a few days later, he was wild with fury.

"Digging for treasure, are they?" he snorted. "I'll get them yet, those two-faced, underhanded robbers. They haven't got no business in these mountains. I'll show them!"

"If they've found a treasure, it's mine! I've hunted for it for years! I'll get it somehow!" Kie Wicks was almost beside himself with rage when he reached the store and told his discovery to Maude.

"Oh, maybe it's not the treasure," Maude tried to soothe the angry man.
"Come eat your supper."

But Kie was too unhappy to eat. He glared about the cheerless kitchen and did not seem to see anything. He stared moodily. Finally he rose and went outside, grumbling like a spoiled child.

He sat for a long time, his head in his hands, not looking up to greet his customers.

"What's the matter with the old man?" inquired a neighbor. "'T ain't often you see Kie Wicks sick or under the weather."

"Somebody's stolen some property from him, and he's thinkin' out a way to get even. Let him alone," counselled Maude. "The more down he seems, the better schemes he can think up. And this one will be a dandy. He ain't eat a bite and he won't talk." Maude seemed quite elated.

It was not until some hours later that Kie came to life once more and demanded his supper. On his face was a determined scowl, as if he were ready to challenge the whole world. As he went into the store he was whistling cheerfully.

Maude smiled at him. But no words were exchanged. That smile expressed everything. Kie had a scheme, a big one, and Maude could afford to wait until he was ready to tell her what it was all about.

Meanwhile on the hill near Orphan Annie, the professor was dreaming of Indian villages and treasure, and with the two watchmen beside him, had no uneasiness.