The warning startled Gordon into an apprehensive survey of his saddle bags. They were quite secure, however, and he followed closely on the mare's heels.

Quickly it became apparent that they were traveling a well-worn cattle path overgrown by the low scrub. It was difficult, but Hazel followed it unfalteringly. Half a mile up this narrow, the great facets of the hills on either side began to close in on them, and still further ahead Gordon discovered that they almost met overhead, the narrowest possible crack alone dividing them.

He was wondering in which direction lay their way out of such a hopeless cul-de-sac when he saw Hazel suddenly bend her body low over her mare's neck, and, at the same moment, she called back a warning to him.

"'Ware overhead rocks!" she cried.

Gordon instantly followed her example, and kept close behind her as she entered a passage which was practically a tunnel. Now their difficulties were increased tenfold. The tunnel, in spite of the narrow split in its roof, was almost dark. The low bush completely hid the track and the little tumbling creek beside the path had deepened to a six-foot cut bank.

Gordon became troubled. But it was not for himself so much as for Hazel. His horse, Sunset, was steady as a rock, but the brown mare ahead was as timid as a kitten. He glanced anxiously at the figure of the girl. The journey seemed not to trouble her one bit. Her mare, too, considering her timidity, was wonderfully steady. No doubt it was the result of perfect confidence in the clever little creature on her back, he thought. His gaze passed still further ahead. He was looking for the termination of this mysterious winding tunnel. But twenty yards was the limit of his vision and, so far, no end was in sight.

Suddenly Hazel's merry laugh came echoing back to him.

"Say, isn't this a great place?" she cried. "It's like one of those enchanted lands you read of in fairy books." Then she added a further warning. "Keep low. We're nearly through."

The horses scrambled on in the semi-darkness. But for Gordon the enchantment of the place was passing, and he was glad to know they were nearly through.

A few minutes later he saw Hazel begin to straighten herself up in the saddle. He followed her example with some caution and considerable relief. The roof was becoming higher, so, too, was the light increasing. Gordon breathed a sigh.

"I don't know about the lunch," he said. "I've bumped the walls for some considerable time. Is there much more of it?"

But before Hazel's reply could reach him his inquiry was answered by the cavern itself. All in an instant they rounded a bend and a dazzling beam of sunlight banished the darkness and nearly blinded him.

Two minutes later he pushed his way through a dense screen of willows, and emerged upon the bank of a beautiful, serene lake of absolutely transparent, sunlit water.

"Behold the spring which is the source of that little stream," cried Hazel, indicating the lake spread out before them. "Isn't it a fairy-book picture? Look round you. Oh, say, I just love it to death."

Gordon gazed about him in wonder. The lake was quite small, but its setting was as beautiful as any artist could have painted it. All around it, on two-thirds of its circumference, a hundred different shades of green illumined the wonderful tangled vegetation. He looked for the place from which they had emerged. It was completely hidden.

Gone, vanished as if by magic. All that remained were the great hills at the back and the wooded banks of the lake at their feet.

He looked down at the water. Clear, clear; it was clear as crystal.

Then he turned towards the sun, and something of the wonder of it all thrilled him. A sea, a calm, unruffled sea of the greenest grass he had ever beheld stretched out before him. Or was it a broad river of grass? Yes, it was a wide river, perhaps two miles wide, with great mountainous banks on either side. To him they seemed to be standing at its source, and its flow carried his gaze away on towards the west, where, above all, miles and miles away, shone the white peaks of the mountains.

The banks of this superb valley were deeply wooded from the base to the soaring summits. Only were the hues of the foliage varied. Right at the foot the green was bright, but less bright than the tall sweet grass. While higher, the dark foliage of pine woods rose somberly on stately towering blackened trunks.

At last Gordon turned back to the girl, who had sat watching the intent expression of his face.

"Tell me," he said, and he made a comprehensive gesture with one hand.

Hazel was waiting only for that sign.

[Illustration: Hazel Was Waiting for That Sign]

"Where we stand now we are twenty miles from the ranch," she said.

"The only other outlet to this valley is twenty miles further on to the west. If you could not find our secret passage again, you would have to travel sixty miles through the most amazing country to get back home."

"Sixty miles back?" Gordon muttered.

"Sure," returned Hazel. Then she laughed. "Even then, unless you'd been pretty well born in these hills you'd never find the way."

Gordon nodded, and glanced in the direction whence they had come.

There was not a sign of the tunnel to be seen. The foliage screen looked impenetrable. He began to smile.

"And your cattle station?" he questioned.

"Come on."

Hazel turned her mare away, and set off at a brisk canter. She followed the line of the hills at the edge of the wide plain of sweet grass.

Gordon followed her, marveling at the place, but more still at his guide. A quarter of an hour's gallop under the shade of the most amazingly beautiful woods he ever remembered to have seen, brought them to a clearing, in the midst of which stood a smallish frame house. It was more or less surrounded by a number of large, heavy-timbered corrals. The whole place was perfectly hidden by the screen of woods from view of the valley beyond.

Hazel leaped out of the saddle and passed hurriedly into the house.

Next minute she returned with two picket ropes.

"We'll picket them both while we eat and get a peek around the place.

We aren't yearning for a twenty-mile tramp back."

Gordon agreed. He remained silent while they off-saddled and secured their horses beyond the woods on the open grass. He was thinking hard.

He was reviewing the purpose which had brought them to this wonderful outworld hiding-place. Nor were his thoughts wholly free from doubts and qualms.

At length the work was done. Their saddle blankets were laid out to dry in the sun, and the saddle bags were emptied of the ample lunch Hazel had carefully provided.

The girl was entirely mistress of the situation. Gordon felt his helplessness out here in the secret heart of nature.

"Shall we eat first or----?" Hazel broke off questioningly.

"Can't we look around the house while the kettle boils?" inquired Gordon, looking up from the fire he had kindled after some difficulty.

He was kneeling on the bare, dusty ground which had been trodden by the hoofs of thousands of cattle in the past.

The girl nodded. Her delight in being this man's cicerone was superlative. This was different from the days she had spent with David Slosson.

"Sure. Come on," she cried. "And there's a well out back where we can fill the kettle."

They hurried off to the well, and, between them, rather like two children, they filled the kettle. Then they returned and placed it on the fire, and again approached the house.

It was a squat, roomy structure of the ordinary frame type, but it was in perfect preservation even to its paint, and Hazel pointed this out as they approached.

"You see this was my daddy's first home," she said. "It's where I was born." She drew a deep, happy sigh. "I seem to remember every stick of it. And my daddy, why, he just loves it, too. That's why, though we don't use it now, he has it painted every year, and kept clean. You see, when my daddy built this for my momma he hadn't a pile of dollars.

It was just all he could afford, and he didn't ever guess he'd have a great deal to spend on a home. We lived here years, and our cattle grazed out in the valley beyond. I used to spend my whole time on the back of a small broncho mare, chasing up and down the hills and woods.

And that's how I found that tunnel we came through. My, but I do love this little place!"

"It's great," agreed Gordon warmly. "I'd call it a--a poet's home."

The girl flung open the front door and led the way in. Instantly Gordon had the surprise of his life. It was furnished. Completely and comfortably furnished. What was more, the furniture, though old, was in perfect repair, and the room looked as though it had been recently occupied.

"When you said 'disused,'" Gordon exclaimed, "I--I--thought it would be empty."

The girl smiled a little sadly.

"No," she said. "We couldn't forsake it. It would be like forgetting my poor momma. No. The furniture and things are just as we used them when she was with us."