driver turned and glanced at Kit, then spoke to Shirley: "How far away do you reckon that lake is, Miss?"
"A mile!" replied Bet decidedly.
"No, it's more than that," corrected Shirley. "I remember of reading somewhere that distances in the desert are very deceiving. It's probably a lot farther off than it seems. I'll say five miles."
"Let's hurry and get there so we can eat our lunch at the water's edge," suggested Joy.
"That's an idea!" replied Matt with a sly glance at Kit. "We'll try and get there by lunch time."
"And look at the lovely trees!" cried Joy. "It's like an oasis in the desert, isn't it?"
But half an hour later they were no nearer the lake than when they had first seen it. A haziness now hung over the water, partly hiding it, and the trees seemed to be floating in mid air.
"That lake might be called 'Lake Illusion,'" laughed Bet. "It certainly is unreal enough! Don't let us wait until we get there to eat lunch. I'm starved. After we've eaten we'll appreciate the view more, anyway."
Even as they watched the mistiness increased and then suddenly seemed to dissolve, leaving the desert stretched out before them, hard, sullen and cruel.
The lake was gone. The waving trees were gone.
Then the girls realized what they had just witnessed. The mirage of the desert! That enticing promise of water that had been the undoing of many a pioneer of the early days!
A thoughtful expression came into the faces of the girls, and their enthusiasm vanished for a few minutes. Stories of by gone days came into their minds, stories of weary travellers who had been beckoned by the mirage and taken miles out of their way by this false promise, perhaps to die of thirst.
"How hard life used to be for the pioneers," said Bet wistfully. "And so easy for us!"
"But why did the pioneers go out on the desert?" asked Joy lightly.
"They didn't have to do it, did they?"
"Of course not, Joy," answered Bet. "But they wanted adventure and they were seeing another sort of mirage. It was the hope of gold and a fortune in the hills."
Bet gazed out over the vast stretch of mesa as if she were living through those early days herself, instead of being carried along by a high-powered car that ate up the miles easily and swiftly.
A low whistle from Matt brought the girls out of their day dreams to follow his glance ahead.
Far along the sandy road was a man trudging along with a bundle over his shoulder.
"That ain't no desert man," said Matt quietly.
"How can you tell from here?" asked Bet.
"You can always tell a desert man by his walk. That fellow looks as if he were used to walking on city streets," Matt returned.
"And he hasn't even a burro," exclaimed Kit contemptuously. "Let's give him a lift and see what he's doing here so far from civilization."
The man ahead had turned at the sound of the automobile, deposited his bundle on the ground and stood waiting expectantly.
The girls smiled as they greeted him. His clothes, a neat business suit and light colored shirt, were soiled, his face was streaked with dust but in his eyes there was that indefinable gleam that marks the soul of an adventurer. He was offered a lift.
"I'm very dusty," said the traveller.
"We don't mind at all," answered the girls. They liked the little man with his far-away look as if he belonged to another world and were seeing sights that no one around him was seeing.
"Isn't he a dear!" whispered Bet. "I like him!"
Little did the girls dream that most of their summer adventures would center around this shabby figure; adventures that would thrill them and at times almost overcome them.
If they had guessed it, they could not have been more cordial in their greeting and more eager to help him. Although none of them realized it, a problem to solve was already presenting itself.
CHAPTER V
A SOLITARY EXPLORER
As Matt Larkin brought his car to a stop, the traveller greeted them as if he were an old acquaintance and had made an appointment for them to meet him at this very spot in the desert and had been waiting and expecting them to come along. He took it as a matter of course that he would be invited to ride and the moment the door of the car was opened he scrambled in with quick, nervous movements.
He was a thin faced little man, stoop shouldered as if he had spent his life bent over books, but there was a charm in his twinkling eyes that made friends at once for him, no matter what society he entered. He was equally at home with people of wealth as he was with the poorest of his friends.
So eager was the old man to be seated, out of the scorching rays of the sun, that he left his bundle lying at the side of the road.
"Your pack!" called Kit, as Matt was about to start the car. "You've forgotten your pack!"
The man gave her a grateful smile. "That's just like me to leave it.
Alicia said I was sure to do just that," he laughed nervously.
He jumped out of the car and quickly recovered his property. "Don't know what I would have done if I'd lost it – all my sustenance and books."
"Listen to the old chap," whispered Joy in Shirley's ear. "He's a regular highbrow. Hear him talk! 'Sustenance', what does that mean?"
"Why, his food, of course," replied Shirley with a laugh.
"Then why didn't he say so? Isn't the word 'food' polite enough for him?" giggled Joy.
"I wonder who he is?" Kit was puzzled by the man. He did not belong to the desert, of that she was sure.
As if in answer to her thought, the stranger announced: "I am Anton Gillette of Dorsey College. I'm on an exploring expedition."
"A professor!" gasped Joy in a low voice. "He'll spoil all our fun. We'll have to pretend we're clever or something of the sort." This was whispered in Bet's ear and brought forth a laugh.
"Be yourself, Joy! Don't try to be clever. It might strain you." Bet leaned forward eagerly and addressed the old man. "An exploring expedition! How interesting that sounds. What are you going to explore? And where?"
"Are you going to find a buried city?" asked Enid excitedly.
"Hardly a buried city in this country," he returned.
"But why? When there were seven cities of Troy and maybe more, why can't it be possible that there is one buried city here?"
"And maybe we could find a King Tut grave," suggested Shirley.
"That's an idea," said Bet, and the girls joined in the laugh, but the professor was serious.
"I don't mind telling you that it is something of that sort that I am after. I want to find the ruins of an old Indian village and find the grave of a certain old chief. How did you guess it?"
"We didn't," laughed Kit. "We were just hoping it might be so."
"This old chief was supposed to have been buried with many historical objects of the tribe, and it is his grave that I must find. It is all very interesting – very," nodded the professor.
"There are Indian mounds all over Arizona," said Kit. "I don't see how you will ever find the right one."
"I have a clue. It may be only an old legend without any foundation of truth in it, but I don't think so. It was at the scene of an Indian massacre. A common enough story it is. The white men encroaching on the Indian lands," began Professor Gillette but Kit interrupted.
"There are thousands of legends like that. They are like the cactus, they grow everywhere in Arizona."
But the old professor was not to be discouraged so easily. "The Indians killed some white men and then soldiers came and there was a massacre – mostly whites."
"There's nothing unusual about that story,