So except for the people of the nearest inhabited island, Antago, a little more than twenty miles to the southwest, Azul Island was little known and untouched.

Only at the southern tip of the island did the mountainous rock break away abruptly to become a low, sandy spit of land where the waves were permitted to roll high upon the shore. This spit was the only part of Azul Island that the people of Antago knew, and very seldom did they have any occasion to visit it.

When they did, they would dock their boats at the narrow wooden pier which was the island’s sole connecting link with the outside world, and set out across the dunes of the windswept reef. They would walk up the spit to a small canyon at the end of which was a sheer wall rising five hundred feet above them. They would stop and look up, knowing this was as far as they could go on Azul Island.

“Solid rock,” they usually said. “The rest of the island is nothing but rock, eight solid miles of it.”

And soon they would leave this desolate, foreboding place, sometimes looking back, once they were at sea, at the bare, yellow rock and the dome-shaped top of Azul Island which gleamed in the sun’s rays.

Never, even by the widest stretch of the imagination, could they suspect that running down the dome was a long, narrow gap which allowed the rays of the sun to find a valley … a lost valley within a lost world; a valley as soft and green and colorful as any tropical island in the Caribbean Sea. And it was inhabited!

Long and narrow, the valley extended almost the length of the island; a bluish-green gem set deep amidst towering walls that were the yellow of pure gold. High up on the wall at the southern end of the valley an underground stream rushed from blackness to sunlight, plummeting downward in a silken sheet of white and crashing onto the rocks of a large pool two hundred feet or more below.

From the great opening where the falls began a trail led down the wall. Halfway to the valley floor it leveled off at a wide ledge fronting a cave. A man sat there, writing. He used empty wooden boxes for his seat and desk, and his pen moved quickly over the paper before him. As he finished each page, he dropped it beside him, and with no hesitation went on to the next sheet.

He was a small man, thin but wiry of build. His knobby knees were uncovered, for he wore tropical walking shorts. Earlier in the day he had put on his white pith helmet to shade his eyes from the glare of the hot sun. He was still wearing the helmet, even though the sun had dropped behind the high walls of the valley. But he hadn’t noticed, for he was much too absorbed in his writing. His round tanned face, usually boyish and jovial, was drawn taut from the intensity of his concentration.

He continued writing until two short whistles broke the stillness of the valley. Looking up, he noticed for the first time that it was sunset. The shadows from the walls had reached the valley floor, turning the cropped grass to an almost brilliant blue. His gaze traveled far up the valley where a band of horses was grazing. He tried without success to locate his friend Steve.

The two short whistles came again. Reaching for his high-powered binoculars, the man brought them close to the steel-rimmed glasses he wore. Near the edge of the tall sugar cane which grew wild on the sides of the valley, he located the boy. Apparently Steve had been sitting there watching the mares and foals since his arrival in Blue Valley a few hours ago. But now he was getting to his feet. The man saw him place his fingers to his lips; again came the two short whistles. Steve was calling Flame, but the stallion was nowhere in sight.

Then from far up the valley came an answering scream. Steve’s whistles were the softest of whispers compared to it. Shrill, loud and clear, it rose to such a high pitch that it seemed it would shatter the towering walls. And when it finally died the valley echoed to the fast, rhythmic beat of pounding hoofs.

The man moved his binoculars to pick up the running stallion. He was coming through the tall cane far up on the opposite side of the valley, the stalks bending and breaking beneath his giant body.