easily upon the two long, jointed metal limbs upon which it had leapt, and continued to keep the lens-tubes turned toward Dan, so he knew that the grotesque metal thing was watching him.

The limbs, he observed, were similar to the hind legs of a grasshopper, both in shape and position. And evidently the thing leapt upon them in about the same way. Then he noticed another curious thing about it.

Three little bars of metal projected above the thickest part of its case, on the upper side. Their ends were joined by a little ring, three inches across. The tiny metal ring glowed with purple luminosity. A purple haze seemed to cling about it, as to the huge ring Dan had seen on the towers above the peak. And suspended inside this ring was a tiny metal needle, shimmering with pulsating white fire.

On the back of this metal monster was a miniature replica of the strange mechanism upon the pinnacle. The little needle pointed up the canyon. A glance that way showed Dan that it pointed at the great device upon the mountain, which looked even more brilliant on this gloomy morning than in the uncertain radiance of the moon. The colossal ring was shrouded in a splendid mantle of purple flame; and the long, slender needle, which seemed to have swung on down to follow Mars below the horizon, still throbbed with scintillating white fire.

For several minutes the two stood there, studying each other. A naked man, tense and bewildered in the presence of mysterious forces—and a grotesque machine, cased in gleaming white metal, whose parts seemed to duplicate most of the functions of a living creature.

Then one of the writhing tentacles that shot from the "head" of the machine reached back under the metal case, and reappeared grasping what appeared to be a flat disk of emerald, two inches across and half an inch thick.

This green disk it held up, with a flat side toward Dan. There was no sound, but a flash of green light came from it, cutting a wide swath into the jungle, and littering its path with smoking and flaming debris.

ut Dan, expecting something of the kind, had flung himself sidewise into the shelter of the boulder beside which he had slept. Behind it, he gathered his feet under him, picked up a rock of convenient size for throwing, and waited, ready and alert.

He heard the soft humming sound on the other side of the boulder. A glittering object flashed above him. Crashing through the brush the metal monster came to earth on the same side of the boulder with him.

But the metal thing had not turned in its flight: consequently its rear end was toward Dan. As it began cumberously to turn about, he hurled his rock with an accuracy that came of a boyhood on the farm. Instinct had made him try for the little ring and needle on the back of the monster, apparently its most vulnerable part.

Whether by luck or skill, the rock struck the gleaming ring, crushing it against the needle—and instant paralysis overtook the metal thing. Its tentacles and limbs became fixed and rigid, and it toppled over in the brush.

Dan walked over to it, and examined it briefly. The green disk had fallen on the ground, and he picked it up. It was made of emerald crystal, it had a little knob of glistening metal set in one side. Rather afraid of it, Dan forebore to twist the knob. But he still clutched it in his hand a few moments later, when, partly for fear that others of its kind would come to succor the fallen monster, and partly to secure shelter from the threatening rain, he retired into the shadows of the tangled jungle.

He spent perhaps half an hour in creeping back to what he supposed a place of comparative safety. For some time he lay there in the cool gloom, brushing occasional insects off his bare skin, wishing by turns that he had a cup of coffee and a good beefsteak, and that he could puzzle out a logical solution of all the astounding things he had met in the island. After the encounter with the metal monster, he felt his theory of the hermit scientists a bit inadequate.

resently his attention was attracted by the unmistakable mew of a kitten. Then he heard the padding sound of cautious human footsteps, and a clear feminine voice calling "Kitty, kitty," in low tones. The steps and the voice seemed coming toward him; since there was no sound of crackling brush, he supposed there was a trail which he had not found.

"Hello," he ventured, when the voice seemed only a few yards away through the green tangle.

At the same instant a gray kitten appeared out of the underbrush, and frisked trustfully across to him. He put out a hand, caressed it, picked it up. In a moment the feminine voice replied, "Hello yourself. Who are you?"

A crackling sound came from the brush, as if the speaker were starting toward him. Dan, abruptly conscious of his lack of attire, said quickly, "Wait a minute! I haven't anything on, you see. I'm Dan McNally. I owned the schooner that something happened to off the island last night."

A delicious, trilling laugh greeted the panic of his first words. Then the clear, sweet voice, serious again, replied, "So you swam ashore from the boat I signaled?"

"Yes."

"Gee, but I'm glad to find you! And you say you haven't any clothes? I wonder what...." The voice paused reflectively, then resumed, "Here's a sheet that I got to signal with in the daytime, if I had a chance. You might wrap it around you until we find something better."

The low, liquid laugh rang out again; again there was a rustling in the brush, and presently an arm appeared, holding a rolled-up sheet.

"All right," he called. "Throw it this way."

n a moment, with the sheet draped around him like a Roman toga, and the kitten on his arm, he advanced to meet the owner of the beautiful voice.

At the trail he met a trim, active-looking young woman, clad in out-of-door attire and with a canvas knapsack on her back. Bareheaded, she wore her brown hair closely shingled. Her face, Dan recognized from the photograph he had seen five years before, though it was more lovely than the splotched newspaper picture had hinted. Her brown eyes were filled with laughter at his predicament and his present unusual garb.

He bowed with mock gravity and said, "How do you do, Miss Helen Hunter?"

Brown eyes widened in surprise. "You know me?" she asked.

"Not half so well as I hope to," he grinned.

Then, handing her the kitten, he spoke seriously. "What about this island? The green flashes? The big machine on the mountain? The metal thing that jumps about like a grasshopper? What's it all about? You know anything about it?"

"Yes, I know a good deal about it," she told him soberly. "It's rather a terrible story. And one you may not believe—no, you've seen them! But the kitten is hungry, and you must be, too, if you swam ashore."

"Well, yes, I am." Dan admitted.

The storm clouds were drifting out to sea; the sun was beginning to assert itself, and it now lighted up the scene with a cheerful brightness. She slung off her pack and sat down cross-legged at the side of the trail. Dan sat down opposite her as she opened the knapsack and produced a can of condensed milk, one of sardines, a can-opener, and half a loaf of bread.

"I had to select my supplies rather at random," she said, "and you'll have to make the best of them."

She started to open the sardines. "You'd better