He ran out of the hut in time to see April dragging Dr. Dacian into a clearing on the south side of the bill. From the opposite side he heard the chatter of machineguns. Cautiously he made his way to wards it until he could make out the shapes of half a dozen white- clad men training their fire on an outcropping.

Napoleon Solo automatically leveled his gun on them and raked their position with fire. Four of them slumped over their guns. One whirled around to confront Napoleon but was chopped down instantly. The last flung himself over his entrenchment and disappeared, presumably to seek a better position. '

A bullet winged close to Napoleon. It came from the helicopters.

Four men, of which Kae Soong was one, were rushing for the machines and spraying fire at Napoleon to cover their escape. He dived for the ground, and just as he did he was lifted bodily from the earth by the impact of a tremendous explosion, then slammed down again, his ears ringing.

All about Solo were falling hot pieces of metal. He rolled to his left under the truck that had carried him to the top of the hill. The truck echoed resoundingly as it was struck a dozen times by fragments from the explosion. Napoleon peered out and saw a mass of tangled rigging where the volcano box had been. Steam swirled around it, but it seemed to have diminished over its previous intensity.

Then he heard the whirling of helicopter motors. He rolled out from under the truck and swore. One of the THRUSH choppers was lifting off the ground. He raised his machinegun and fired, aiming for the pilot, but it faded quickly away from the hilltop.

The other chopper was waiting, rotors whirling, while a burly man, limping perceptibly, was assisted inside. It was Kae Soong. The man had either received a superficial leg wound during the late unpleasant ness or had sprained his ankle in the process of fleeing.

Without hope, Napoleon Solo trigger a blast at him, but the bullet-proof door had slammed closed. Already the whirlybird was leaving the ground in a swirl of dust.

Out of nowhere, he remembered what Waverly had once told him.

"Bringing down one of those with ground fire is an act of God, plus a lot of luck," Waverly had said. "But if you ever have to try, forget the men; aim for the base of the rotors. You've got one chance in maybe a thousand to hit it. But if you do, it's big casino."

For a moment the slanted angle of the copter's rise had the exact base of the rotors out of sight and by the time it had veered back again a lot of distance had come between them.

Grimly, Napoleon Solo sighted for the slim base and poured the last of his clip out into the empty air.

He was shaking his head in futile rage when he heard Illya's shout. What he saw made him tense, unbelieving.

Directly under the whirling rotors a spot of flame, no bigger than a tennis ball, had flowered. While he watched, it spread to the size of a soccer ball, turned bright scarlet.

Whoosh!

Like an evil flower, the entire machine was enveloped in that scarlet curtain. Through it Napoleon Solo could see the men inside leaping around in panic. And directly after that the world exploded, so violently that he could feel the concussion of the blast even at that distance.

The copter was no more. And of the men in it, scattered bits of clothing and worse were plummeting down through the flames.

Illya Kuryakin said, "I've seen worse shots, Deadeye."

Napoleon nodded. He felt very tired, very humble. Together they went across the plain to see what was left.

The four of them gaped into the still-steaming shaft. Then they walked to the other side of the hill and awaited the rescue copters, which Illya Kuryakin had called in on his communicator, to arrive.

Napoleon was grinning, but Illya looked dejected. "What's the matter?" he asked his Russian companion.

"Everything. That other copter got away and maybe with the formula. We're quite possibly worse off than before.

"Now it's not just Singapore. It's anywhere and everywhere. They'll be planting these devices like rice grains."

"No they won't," said Dr. Dacian weakly.

"Why not?" April Dancer asked.

"Because I gave them a false formula."

They sighed, then lay back and looked at the sun breaking through the steam-cloud over the hill. Suddenly April sat up, her eyes round with horror. "Oh gosh!"

"What is it?" they asked all at the same time.

"It's the end of the world!"

They looked at her gravely, as if they'd left out some vital factor in their considerations.

"I left poor Don Wirts watching that car," she exclaimed. "He must still be there. We must get to him right away."

They laughed, and turned their eyes south as the black specks of friendly helicopters materialized on the horizon.