As the helicopter-plane dropped to within a few hundred feet of it, a strip of the sea verdure split in two and reared up. It looked, at first, like magic. But from aloft Chris saw the trick and how the camouflage was worked. What appeared to be a slice of the jungle roof was, in reality, a metal framework cunningly plastered with layers of green growth. An oblong, some fifty by a hundred feet, it parted in the middle like a bridge that opens to let a steamer through, revealing the lair of the plane. Soon more was revealed. Two tiny, green-painted huts stood in the minute clearing, and a few white-clad figures were by them, staring up at the plane sinking down and at the other plane which soared above like a buzzing mosquito. One of the dwarfed figures in white waved an arm. The others around him darted into the left-side hut. Then the helicopter-plane's wheels touched the small space allotted for it in the clearing, and the whirling propellers halted. "So that's the secret!" Chris muttered. He pulled the microphone of the radio-telephone to his lips and angled with the dials for connection with the fleet hundreds of miles behind, meanwhile noting his exact position on Azuero Peninsula. But before he spoke, some sixth sense bade him glance below once more. An icy shiver gripped his body. A thin slit had appeared in the roof of the left-side hut. A spot of bright blue light was winking evilly inside it. And, though he could not hear it, Chris knew with terrible certainty that a shrill, impatient whining was piercing from the machinery of a weapon inside that hut--a weapon whose fangs had forked close to him once before--a weapon which the winking eye of blue presaged. It struck. But at the same instant Chris leaped desperately from the cockpit of the scout. * * * * * He leaped almost into the teeth of the blue-tinged ray which knifed up with uncanny accuracy from the slit in the roof of the hut. He was conscious of a flash of unearthly light, of terrible heat which came with it. Only the force of his jump saved him. He pulled the ripcord of the 'chute strapped to him and jerked to a pause; then he was swinging beneath a mushroom of white, trembling as he stared at the fate he had missed by a hair's breadth. A web of spectral blue light had enveloped the abandoned scout. The plane appeared to shudder, hanging almost motionless in the wraith-like mist. Then, with a crackle, the wings and tail shivered into countless fragments; the stripped fuselage nosed over and plunged earthward, a roaring mass of flames. A fiery comet, it screamed past the man who swayed beneath his 'chute, coming within a few hundred feet of him and searing him with its hot breath. Then it drove into the dense flanks of the jungle growth. Soon only a charred skeleton marked the last landing field of a scout of the dirigible ZX-1. "And now, I guess," Chris whispered, "they'll turn that ray on me...."