It will be impossible to skid that amount of dead weight.

"You're the Maintenance Captain," Otakar said. "So you are the one to answer that question best."

"I know the answer. With the power dead the manual disengage lever has to be used. But the trouble is that the thing is clamped to the inside rear wall. It has to be unhooked, fitted into place, then turned about a dozen times. All of this under, what? about three meters of water. Do you swim, Otakar?"

"Where would I learn to do that?"

'A good question. Too much fertilizer in the ca.n.a.l to swim there-and that is the only body of water near the city. You think someone would have planned a swimming pool when the cites were designed. It wouldn't have taken much. I imagine that leaves me as the only swimmer on Halvmo~rk. A reluctant volunteer. But I'll need some help."

There was no easy way to make a face mask, but one of the pressure bottles filled with compressed air was simple enough to arrange. Jan worked with the valve until it released a steady flow of air, smelling of oil and grease, that should supply his needs without blowing his head off. Emo arranged a sling so he could carry it at his waist, with a plastic tube to his mouth. That and a waterproof light were all he needed.

"Bring us as close as you can," he told Otakar as he stripped off his clothes. He kept his boots on. The metal would be hot, and he would need gloves as well. When the two machines were touching, nose to nose, he cracked the top hatch. A wave of burning air rolled in. Without a word he climbed to the hatch and pushed it open.

It was like climbing into a baker's oven. The cool air of the engine was left behind in an instant as he emerged into the blinding, burning sunshine. He covered his eyes with his arm and shuffled the length of the engine's roof, picking his way between the cooling fins. Trying not to gasp in the hot air, forcing himself t6 suck the cooler air from the tube instead. Though the soles of his shoes were thick the heat of the metal was penetrating already. At the edge he did not hesitate, but eased himself over into the water.

It was a steaming cauldron that drained the energy from his body. One, two, three, strokes took him to the open hatch on the tank and he did not permit himself to hesitate, but sank instantly beneath the surface. It was dark, too dark-then he remembered the light. The heat of the water about him was all engulfing, draining both his will and energy. Now the lever, he must get it.

Everything moved as slowly as in a dream, and if his chest hadn't hurt he thought he might go to sleep.

He was getting air from the tank, but not enough. The lever. It came free easily enough, but fitting it over the stud seemed immensely difficuk. When it finally clicked into place he lost precious seconds trying to remember which way to move it. Then the turns, over and over until it would turn no more.

Time. Time to go. The lever and the torch dropped from his fingers and he tried to rise, but he could not.

The light of the open hatch was clear above but he did not have the strength to swim up to it. With a last burst of his waning energy he tore the weight of the air tank away, spitting out the tube, and bent his knees. One last time. Pushing upward, swimming u p ward, hard, harder.

His hands came out of the water and clutched the edge of the hatch. Then his head was above the surface and he sucked in great gasps of the burning air. It hurt, but it cleared his head. When he was able, he dragged himself up and staggered across the top of the tank and threw himself in the direction of the engine.

And knew he could not make it, could nQt swim another stroke.

The rope splashed into the water beside his head and he clutched it reflexively. He was pulled to the engine, to the side, and Otakar reached down and took him by the wrists and pulled him from the water like an expiring fish. Jan was barely aware of this, his consciousness fading in a red haze, until his leg brushed the metal of the engine's roof, searing the flesh almost to the bone. He shouted aloud at the sudden pain, his eyes wide, aware that Otakar was helping him. Otakar without a coldsuit, gasping with exhaustion.

They leaned one on the other as they made their way carefully across the top of the engine. Jan went down first, helped by the co-driver, who followed behind him. The air inside was arctic. For a long time all they could do was sit where they had dropped on the floor, fighting to recover.

"Let us not do that again if we can avoid it," Jan said, finally. Otakar could only nod weak agreement.

H yzo put burn cream on Jan's leg, then wrapped it in gauze. It was painful, but a pill took care of that.

And his fatigue as well. Dressed again, he sat in the driver's chair and checked his controls.

'Any sign of leaking yet?" he asked the engineer.

"Negative. This beast is tight."

"Good. Give me plenty of power. I'm going to push that tank off the Road. What will I break if I push it nose to nose?"

"Couple of lights, nothing important. We have solid steel there, four centimeters thick. Weight for traction. Just push."

Jan did, easing forward at slowest possible revs until metal ground against metal and the engine shuddered. Keeping in the lowest gear he pressed down steadily on the accelerator. The clutches growled deeply and the entire engine shuddered as it fought against the dead weight of the tank.

Something had to give.

The tank moved. Once it had started to roll back-ward, Jan kept the speed steady and turned the wheel ever so slightly, centering it again to hold the gradual turn. Bit by bit they turned until they left the cable behind and the tank was pointing at right angles to the Road. Jan centered the wheel and went on.

Further and further from the center. Closer and closer to the edge.

Suddenly the tank reared up and Jan hit the brakes. It dropped over the edge instantly and, from the angle, the engine was just at the edge itself. Slowly and carefully he put the engine in reverse and backed away from the danger. Only when they were lined up again in the center of the Road did he let the air out of his lungs with a deep sigh.

"I agree," Otakar said. "I hope this is the last of the trouble here."

It was not easy, but there were no major problems in bringing the trains across the drowned stretch of Road. Just time. Wasted time. The cars, far lighter than the ma.s.sive engines, had a tendency to float in the water. Two were the most that could be taken through at one time, and this possible only with an engine at either end. The shuttle continued without stop until all of the cars were across. Only when the trains had been a.s.sembled on the far side of the drowned section did Jan permit himself to relax, to sleep for more than a few hours at a time. He had ordered an eight hour rest period before they continued.

Everyone needed it, the engine crews were exhausted, and he knew better than to press on with the drivers in this condition. They could rest but he could not. During the entire operation of moving the trains across the drowned section of Road he had been worrying away at a problem that refused to be dismissed. An obvious problem that faced him squarely when he drove back over the water-covered Road to the squadron of solitary tanks. He stopped the water-streaming engine next to the tanks, pulled on a coldsuit, and transferred to the lead tank.

"I thought you had forgotten about us," Lajos Nagy said.

"Quite the opposite. I've been thinking of nothing else for days."

"You going to leave the tanks here?"

"N~we need them too much."

'~ut we can't cross under our own power.

"I don't expect you to. Look at this."

Jan unrolled a blueprint, a side projection of one of the tanks. He had marked it up liberally with a large red pen. He tapped the lines he had added.

"These are our problem areas," he said. "We are going to spray them all with mothball sealant. So they should be watertight long enough to get through the water and out on the other side."

"Wait a bit," Lajos said, pointing to the diagram. "You've got all the exit hatches sealed shut. How can the driver get out if he has to?"

"No drivers. We take the treads out of gear, seal the tanks watertight-then tow them across. A single cable will do for each. I tried it and it works."

"I hope so," Lajos said dubiously. "But I would hate to be in the engine towing one of these things if it went off the edge of the Road. It will pull the engine over with it."

"It might very well. That is why we are going to rig a tow release that can be operated from inside the engine. If the tank starts to go we just cut it loose."

Lajos shook his head. "I suppose there's nothing else for it. Let's try it with number six tank first. The clutches are almost shot and we may have to leave it behind in any case.

There was a unanimous sigh of relief when the plan worked. The towed tank vanished beneath the water and wasn t seen again until it emerged on the other side of the sunken section of Road. The sealant was quickly sc.r.a.ped away and, except for a few puddles from a small leak, the tank was intact. The transfer of all the others began.

When the trek was ready to begin again the relief co-drivers were brought back to the engines. Alzbeta was carrying a sealed bundle that she set down when she took off her coldsuit.

"Something special," she said. "I made it myself. It is a family recipe for special occasions. I think this is a special occasion. Beef stroganoff."

It was delicious. The crew sat down to the first meal they had enjoyed since the trek had begun. There was freshly-baked bread with it, liters of beer and fresh green onions. There was even some cheese to follow, though few, if any, had s.p.a.ce for this. But they groaned heroically and made room for it.

"Our thanks," Jan said, taking her hand despite the presence of others. No one complained; apparently no one even noticed. They accepted Alzbeta as part of the crew now; an improved part since no one else could do a thing about meals other than heat frozen concentrates. Jan had a sudden inspiration.

"We'll be rolling in about a half an hour. That's just about time to check you out in the driver's seat, Alzbeta. You don't want to just be a co-driver all your life."

"Good idea," Otakar said.

"Oh, no, I couldn't. It's just not possible."

"That's an order, see you obey it." His smile softened the impact of his words, and a moment later they were all laughing. Hyzo went for a rag and polished the chair for her; Otakar led her there and adjusted the seat so she could reach the pedals easily. With the power off she tentatively stepped on the brakes and accelerator and tugged on the steering wheel. She already knew the func-tion of all of the instruments.

"See how simple it is," Jan said. "Now put it in reverse and back a few feet." She went pale.

"That's different. I wouldn't be able to."

"Why not?"

"You understand, it's your work."

"For men only, you mean?"

"Yes, perhaps I do."

"Then try it. You have been doing men-only work for the past week, you and the other girls, and the world hasn't come to an end."

"Yes-I will!"

She said it defiantly-and meant it. Things were changing and she liked the changes. Without a word of instruction she turned on the engine, disconnected the autopilot and did all the other things needed to ready the engine. Then, ever so tentatively, she engaged the reverse gear and backed the engine a bit.

Then, when she had shut down the engine again, everyone cheered.

When the trek began again they were all in the best of moods, rested and happy. Which was a good thing, since the worst part of the journey was coming up. The engi-neers who had built the Road had done their best to avoid all the natural hazards of the planet. As much as possible of the Road stayed behind the coastal mountain barriers of the two continents. The penetration of the mountains themselves was done by tunnel. The coasts were avoided for the most part by putting the Road on the dikes offsh.o.r.e. On the raised chain of islands, the isthmus that connected the two continents, the Road ran high along the spine of the islands, the high mountain ridges.

But there was one hazard that could not be avoided. Everitually the Road would have to cross the tropical jungle barrier. The southernmost part of the continent was eternal burning summer. With the air temperature just a few degrees below the boiling point of water, this was a jungle h.e.l.l.

The Road turned back inland briefly, plungi~ng through a mountain range. The tanks were thirty hours ahead and working on clearing the Road, so Jan had reports on the conditions. But, as always, the reality was beyond descrip-tion. The tunnel fell at a steep angle and his headlights glared against rock and Road.

There were letters here, etched eternally into the surface of the Road itself, SLOW they read, SLOW repeated again and again. The tires rumbled as they crossed the pattern of letters. As the glaring mouth of the tunnel appeared ahead the trains were doing a lumbering 50 kilometers an hour.

Trees, vines, plants, leaves, the jungle burst with life on all sides, above, even on the Road itself. The Road was over 200 meters wide here, twice the normal width, and still the jungle had overrun it as the burgeoning plant life fought for the light of the sun. In the four years since they had pa.s.sed last the trees on either side had sent long branches out, questing for the light. Many times these had grown so large that they had overweighed and toppled the parent trees onto the Road. Some had died and been used as a base for other plants and vines, while others, with their roots still fixed in the jungle, had thrived and grown higher from their new positions. Where trees had not obstructed the Road, creepers and vines, some a meter thick and more, bad crawled out onto the sunny surface.

The tanks had joined in battle against the trees; the black remains of their victories lined the Road on both sides. With their flame-exploding snouts, the fusion guns had gone first, burning every obstruction before them. Then dozer blades had cleared a path just wide enou~h for their treads: the tanks that followed had widened this, pushing back the charred remains. Now the trains moved slowly between two walls of blackened debris, still smoking in places. It was a nightmare sight.

"It's horrible," Alzbeta said. "Horrible to look at."

"I don't mean to make light of it," Jan told her, "but this is just the beginning. The worse part is up ahead.

Of course it is dangerous out there, always, even when the trip is made at the usual time. And we are late this year, very late."

"Will that make a difference?" she asked.

"I'm not sur~but if there is going to be any differ-ence it will be for the worse. If only better records had been kept. I can't find anything at all from any early planetary surveys. All the memory tapes have been wiped clean. Of course there are logs of all the trips, but they aren't very helpful. Technical notes and distance for the most part. But no personal journals of any kind. I suppose when everything has to be packed to be moved every couple of years odd items usually get thrown out. So I have no hard facts~ust a feeling. It's spring that's bothering me.

"I do not know the word"

"Not in the language. No referent. On more reason-able planets there are four seasons in the temperate zones. Winter is the cold time, summer is the hot. The time in between, when everything is warming up, that's spring."

Alzbeta shook her head and smiled. "It is a little hard to understand."

"There is something a little bit like it on this planet. At the edge of the twilight zone there are life forms that have adapted to the cooler evironment. They have their ecological niche there and make out fine until summer returns. When it does, all this burgeoning hot-zone life will probably rush in and make a meal of the cooler-adapted forms. Everything out there is eat and be eaten, so the compet.i.tion for a new food source must be some-thing fierce."

"But you can't be sure "I'm not sure-and I also hope that I am wrong about it. Just cross your fingers and hope that our luck holds Out."

It didn't. At first the change seemed innocent enough, just a little incidental traffic slaughter of no real impor-tance. Only Alzbeta seemed put out by it.

"The animals, they don't seem to know about ma-chines. They just come out onto the Road and are run over, crushed."

"There's nothing we can do about it. Don't look if it bothers you.

"I must look. That is part of my job. But those little greenish things with the orange bands, there seem to be a lot of them, coming out of the jungle."

Jan noticed them now, first individuals, then groups, more and more of them. They were like obscene parodies of terrestrial frogs that had grown big as cats. A ripple of movement seemed to go over them as they advanced with a jerking, hopping motion.

'A migration, maybe," he said. "Or they could be chased by something. It's messy-but they can't hurt us.

Or can they? As he spoke the words Jan felt a sudden disquiet. The edge of a memory. What was it?

But any doubts at all called for caution. He switched off the speed control and let off on the accelerator, then turned on the microphone.

"Leader to all trains. Decrease speed by 20 K's now!"

"What's wrong?" Alzbeta asked.

The Road was becoming almost invisible, covered by the creatures that thronged across it, oblivious of the deadly wheels rushing toward them.

"Of course!" Jan shouted into the microphone. 'All drivers stop, stop. But don't use your brakes. Ease off on the power, power down to zero, but watch your coupling pressure gauges or you'll jackknife.

Repeat. Slow without braking, watch your coupling pressure, watch your nose radar for the train ahead of you."

"What's happening? What's wrong?" Emo called in from the engine compartment.

'Animals of some kind, covering the Road, thousands of them, we're running them down, crushing them....

Jan broke off as the engine lurched sideways, then he lashed out his hand to cut off the automatic steering, and clutched at the steering wheel.

"It's like driving on ice... no friction... the wheels are beginning to slide on the bodies"

And the cars were beginning to go too. In the moni-tor screens Jan saw that the whole train was beginning to wriggle like a snake as the cars skidded and the steering computer fought to keep them following in a straight line.

"Get the computer out of your steering circuits," Jan ordered the other drivers, throwing the switch himself at the same time. A touch of power pulled ahead on the train and stopped the weaving for the moment. He dropped the speed again, slowly, slowly, plunging on into the solid wall of bodies.

"Jan, look ahead!"