“I never heard of this ocean-draining phenomenon before,” Northrop said. “Is it common?”
The geologist shook his head. “As far as I know it’s unique. In my view it’s a cusp event related to the exact magnitude of Tenacity’s mass. Rock porosity is perfectly common, of course. It’s caused by vulcanism. Volcanoes result from the melting of a planet’s basaltic mantle. The melt is never uniform: it occurs at dihedral angles between rock crystals. The melt regions then join up to create a network, and in effect the rock becomes a sponge filled with molten material, which pressure forces to the surface and you have an eruption. Normally the sponge is then filled up with more mantle rock, acting elastically over long periods of time.
“What seems to have happened on Tenacity is that the interstices left by vulcanism were never filled up. If the planet had been only slightly smaller there would have been little vulcanism and so no giant porous regions. Any larger and pressure from below would certainly have filled up the interstices, instead of leaving a layer of sponge ready to soak up all the surface water.”
“So it all hangs on a fine balance, eh?”
Northrop had followed the explanation absent-mindedly. He glanced overhead. The lighter dispatched by O’Rourke was descending at reckless speed, optical distortion from its inertial field resembling heat haze. Like a thrown cushion, it plumped down on the yellow sand.
“See you, Roncie. Wish me luck.”
“Sure.”
Castaneda climbed into the lighter. Northrop watched it fling itself into the air and streak into the distance, swiftly disappearing.
A movement on the near horizon, in the direction of the small, bright sun, caught his attention. The terrain rose somewhat there, forming a low ridge. Northrop took out a magnifier and pointed the scope.
On the small screen, two vehicles were sliding down the ridge, piling sand in front of them. One was boat-like, lacking any wheels that he could see, and ploughed through the sand as though through water.
The other was larger, an ungainly contraption with big wheels which flashed as they revolved. Both craft seemed to be moving with haste, and the large one was having trouble negotiating the slope at such speed. Once, it nearly turned over.
Soon, Northrop saw the reason for such hurry. The vehicles were fleeing from pursuers which sought to cut them off, large flat hovercraft—or so it seemed—which blew up sand around their edges. Three of them soared over the ridge.
All five vehicles were heading this way.
For day after day Hrityu and Kurwer had followed their Artaxan ally across the desert. The Artaxan camp, he promised them, was now not far off.
It was as the sun was descending on the third day that the blowcraft found then. In them were both Crome and Gamintes—a combination of sinister import to the Analane.
Karvass immediately turned his vehicle aside, followed by the Analane. They were attempting to lose themselves among the dunes before being spotted. The hope was futile: the three blowcraft came surging over the sand in pursuit. The blowcraft, which travelled by lifting themselves off the ground by means of a blast of air, were little more than moving platforms surrounded by balustrades. They were packed with gesticulating, yelling warriors. A carelessly aimed flenching blade whirred over Hrityu’s head. Kurwer grabbed his own flinger ready to retaliate, but it was clear the three travellers could not hold their own and would quickly be overwhelmed.
“Follow me!” Karvass called out.
Again he turned his vehicle and went coursing at full speed towards a long ridge in the middle distance. Hrityu placed his own vehicle’s outer wheels on maximum gearing. Briefly they slid on the sand before the craft picked up speed. He could see what the Artaxan’s strategy was. He was counting on the blowcraft being unable to mount the ridge, allowing time to make an escape.
This was one of their disadvantages. Otherwise blowcraft were favoured by raiders roaming the desert looking for prey, as on level ground they were capable of quick bursts of speed. The war whoops grew louder as the pursuers gained on their victims. By now Karvass had reached the foot of the ridge and the prow of his craft heaved itself on to the slope, hurtling straight up it with ease. The Analane were not far behind; but their own vehicle could not climb nearly as swiftly. Hrityu turned first left then right so that the big wheels could bite into the hillside, mounting zigzag fashion.
Atop the ridge he paused and looked down. All three blowcraft had launched themselves on to the slope. The curtains holding in the cushions of air on which they floated flapped and bulged with the effort. But after mounting so far, they all began to slide back down.
Kurwer laughed. “So much for them!”
His glee was short-lived. Once again the blowcraft attempted the slope, adopting a zigzag tactic of their own and attacking the hillside slantwise. Slowly, slipping as rotating, the occupants hanging on to the balustrades, they were approaching the summit.
Hrityu hastily put the wheelcraft in motion again, hurtling down the other side of the ridge and nearly overturning in his hurry. Suddenly Kurwer pointed.
“Look!”
As he struggled to control the wheelcraft Hrityu glanced sidelong in the direction Kurwer indicated. Not too far off, there was a camp of some sort. There were pavilions—though only small ones—and what looked like big machines.
Only the Tlixix erected pavilions, but they were very big ones, and anyway it was inconceivable to find Tlixix out here in the wilderness. The machines, too, were unfamiliar.
Nevertheless the unknown camp presented an opportunity which the quick-thinking Karvass immediately seized. He made for the camp, followed by the Analane. Depending on whoever was in the camp, they might find allies or at least disconcert their pursuers.
On the other hand, Hrityu admitted to himself, the camp might contain yet more enemies.
Once having heaved themselves over the ridge the blowcraft slid down it with alacrity and shot across the desert, fanning out.
On the edge of the strange camp, the two fleeing craft found themselves caught in a deadly triangle.
All five vehicles now came to a stop. Gamintes and Crome clambered from their craft. They stood waving their flingers, jeering and laughing.
“We are lost,” Kurwer muttered. “What aid will there be for our tribe now?”
Hrityu took time to notice the inhabitants of the camp. They were humanoid, but their bodies were clad in material of some kind. They were pale green in colour, and lacked head crests. Three stood by one or the big machines. Another had just emerged from one of the little pavilions.
Suddenly Hrityu realized where he had seen their like before—in the Pavilion of Audience, where members of a strange tribe had been accused of stealing the radiator.
And, incredibly, had swallowed water.
A Crome voice floated across the air. “Ho, Analane! Do you see our Gaminte brothers with us? They know that we have requested a war of extermination, and say the Tlixix are certain to agree. They are here to join us in the sport. We allow you the honour of being the first to face death!”
“So that is why the Gamintes are travelling with our enemies,” Hrityu said grimly to his friend. “The Tlixix want us out of the way quickly. I wonder why?”
“It was ever their way,” Kurwer replied dolefully. “They see some advantage in cultivating the Crome. Perhaps they wish to use them as they use the Gamintes.”
“Let us hope they all perish together when the Artaxan alliance strike!”
Hrityu picked up his flinger. They stepped down from the wheelcraft and crouched beside it for what cover it gave. Flenching blades clanged against the side of the vehicle. Uttering ululating cries, a group of Crome charged.