World Of Ptavvs

As they did.

The ship was almost down, hovering motionless a few miles west of the beginning rise of the Crescent. A pillar of fire licked a mile down to touch the surface. Where it touched, the surface disappeared. A channel like the bed of a river followed below the ship, fading into the darkness beyond the reach of the light.

The ship rode with nose tilted high; the fusion flame reached slightly forward. Gently, gently, one mile up, the Golden Circle slowed and stopped.

Where the flame touched, the surface disappeared. A wide, shallow crater formed below the descending ship. It deepened rapidly. A ring of fog formed, soft and white and opaque, thickening in the cold and the dark, closing in on the ship. Then there was nothing but the lighted fog and the crater and the licking fusion fire.

This was the most alien place. He had been wasting his life searching out the inhabited worlds of the galaxy; for never had they given him such a flavor of strangeness as came from this icy world, colder than… than the bottom of Dante's Hell.

'We'll be landing on the water ice layer,' the pilot explained, just as if he'd been asked. He had. 'The gas layers wouldn't hold us. But first we have to dig down.'

Had he been searching for strangeness? Wasn't that a Greenberg thought slipping into his conscious mind? Yes. This soul-satisfaction was the old Greenberg starlust; he had searched for wealth, only wealth.

The crater looked like an open pit mine now, with a sloping ring wall and then an almost flat rim and then another, deeper ring wall and… Kzanol/Greenberg looked down, grinning and squinting against the glare, trying to guess which layer was which gas. They had been drilling through a very thick blanket of ice, hundreds or thousands of feet thick. Perhaps it was nitrogen? Then the next layer, appearing now, would be oxygen.

The plain and the space above it exploded in flame.

'She blows!' Lew crowed, like a felon reprieved. A towering, twisting pillar of yellow and blue flame roared straight up out of the telescope, out of the pale plain where there had been the small white star of the Golden Circle. For a moment the star shone brightly through the flames. Then it was swamped, and the whole scope was fire. Lew dropped the magnification by a ten-factor to watch the fire spread. Then he had to drop it again. And again.

Pluto was on fire. For billions of years a thick blanket of relatively inert nitrogen ice had protected the highly reactive layers below. Meteors, as scarce out here as sperm whales in a goldfish bowl, inevitably buried themselves in the nitrogen layer. There had been no combustion on Pluto since Kzanol's spaceship smashed down from the stars. But now hydrogen vapor mixed with oxygen vapor, and they burned. Other elements burned too.

The fire spread outward in a circle. A strong, hot wind blew out and up into vacuum, fanning great sheets of flame over the boiling ices until raw oxygen was exposed. Then the fire dug deeper. There were raw metals below the thin sheet of water ice; and it was thin, nonexistent in places, for it had all formed when, the spaceship struck, untold eons ago, when food yeast still ruled Earth. Sodium and calcium veins; even iron burns furiously in the presence of enough oxygen and enough heat. Or chlorine, or fluorine; both halogens were present, blowing off the top of Pluto's frozen atmosphere, some burning with hydrogen in the first sheets of flame. Raise the temperature enough and even oxygen and nitrogen will unite.

Lew watched his screen in single-minded concentration. He thought of his future great-great-grandchildren and wondered how he could possibly make them see this as he saw it now. Old and leathery and hairless and sedentary, he would tell those children: 'I saw a world burning when I was young…' He would never see anything as strange.

Pluto was a black disc almost covering his scope screen, with a cold highlight near the sunward arm. In that disc the broad ring of fire had almost become a great circle, with one arc crawling over the edge of the world. When it contracted on the other side of the world there would be an explosion such as could only be imagined. But in the center the ring was darkening to black, its fuel nearly burned out.

The coldest spot within the ring was the point where the fire had started.

The Golden Circle had gone straight up, ringing and shivering from the blast, with sheets of fire roaring past the wing and hull. Kzanol/Greenberg had the wind knocked out of him. Kzanol was just now recovering consciousness. The ship was not yet harmed. It certainly hadn't been harmed by the heat of combustion. The ship's underbelly was built to withstand fusion heat for weeks.

But the pilot was out of control. His reflexes had taken over at the instant the shock wave hit, and then his conscious mind… He found himself his own master for the first time in weeks, and he made his decision. He turned off the fuel feed. The drive couldn't possibly be started again. Kzanol raged and told him to die, and he did, but it was too late. The ship, deprived of power, bucked and swooped in the burning wind.

Kzanol/Greenberg cursed fluent and ancient English.

Below him a wall of fire tens of miles high retreated toward the horizon. The ship hadn't turned over; the gyros must still be working.

The buffeting from below eased as the firelight died. The ship began to fall.

Deliberately, reluctantly, Lew took his eyes off the screen and shook himself. Then he turned on the radio. 'All ships,' he said. 'Drive to Pluto at max. We can watch the fireworks on the way. Tartov, program us a course to land us on the dawn side of whatever's left of Cott's Crescent. Hexter, you haven't done anything useful lately. Find Ceres with a maser so I can fill them in to date. Comments?'

'This is Tartov. Lew, for Pete's sake! The planet's on fire! How can we land?'

'We've got four million miles to drive. The fire should be out when we get there. Oh, all right, get us into an orbit, but you're still gonna program our landing.'

'I think we ought to leave a ship in orbit. Just in case.'

'All right, Mabe. We'll gamble for who stays up. More comments?'

Three men and a woman pushed buttons that squirted volatilized uranium into fusion tubes and followed it with hydrogen. A growing storm of neutrons produced fission which produced heat which produced fusion. Four blue-white stars formed, very long and very thin. The bright ends swung toward Pluto. They began to move.

'That's that,' Masney said wearily. 'And a good thing, too. Do you suppose there ever was a telepathy amplifier?'

'I'm sure there is. And it's not over yet.' Luke was flexing his fingers and looking worried. Pluto showed on the screen before him, with the edge of the fire a straight line creeping west to east. 'Lloyd, why do you think didn't want the Belt to beat us to Pluto? Why did we come after them, anyway? That amplifier is a new weapon! If the Belt takes it apart and makes one that humans can use, we could see the worst and most permanent dictatorship in history. It might never end at all.'

Masney looked at the future Luke had painted and, judging by his expression, found it evil. Then he grinned.

'They can't land. It's all right, Luke. They can't get down to the helmet with that fire going.'

'That fire isn't burning any more where the honeymooner came down.'

Masney looked. 'Right. Is Pluto still explosive?'

'I don't know. There might still be pockets of unburned material. But they can go down if they want, regardless. All they have to do is land on the day side, where there's no hydrogen, and land so fast they don't burn through the nitrogen layer. They'd sink into it, of course, from heat leakage through the hulls, so they'd eventually have to dig their way out. But that's nothing. What counts is the hydrogen. Miss that and you probably won't start a fire.

'Now, they'll almost certainly go down for the amplifier as soon as the fire stops. We've got to destroy it before they get it. Or after.'

'Take a look,' said Lloyd.

Four bright points formed in a cluster on the screen. In seconds they had grown into lines a mile long, all pointing in the same direction.

'We've got some time,' said Masney. 'They're millions of miles from Pluto.'

'Not far enough.' Luke reached to close the intership circuit. 'Calling Heinlein.