The brutal heat of the star curdled the air. Waves of it banked across the desert, distorting the horizon and forming a lens. Saddled atop his ill-tempered sandsteer, Corvik could see for leagues.

"About another four miles," said Vim, shielding the screen of his palm map from the light.

"Still an hour then," said Corvik, swatting at an insect on his arm. "For a creature that doesn't sweat, this thing smells really bad."

As though in answer, the sandsteer snorted, a globule of pale phlegm thudding wetly into the ground.

"Be nice, Corvik, said Vim. "She's bought you this far - and moaned a lot less than you."

Corvik patted the sandsteer's flank and mopped his brow with a damp handkerchief. "I just still can't believe the penny-pinchers in the office. A project set to launch a billion-dollar tourist industry and they can't cough up for a couple of track motors and a decent trailer. What's that, a few grand?"

Vim sighed. "Think of your salary, Cor. They'd have been happy to take it out of that. Besides, you wanted an intrepid lifestyle, right? Well, look around you. This is it." Behind them, the wide footprints of the sandsteer trailed off into the distance, broken up by the winding track lines of their two sledges. Each was laden with several vats of lukewarm water and the bulk of their survey and rap-kit.

"One more drop and we're out of here," said Corvik. "It's been a long three weeks, Vim."

"I know, I know," said Vim, rolling his eyes. "We'll be on our way soon enough. You should be home to pester your Ex by the 9th."

Corvik looked back and forth over the wide, empty expanse of the desert

He couldn't have agreed more.

The Mundan plateau was a fifteen mile expanse of sun-baked limestone. From the cracks in a largely smooth surface, hardy plants pressed thick leaves into the air, scratching a living from the condensate that formed in the hours of darkness. The wide-toed sandsteer moved easily over the sand as it tapered into rock. The cave entrance was located a mile and a half further in. "The Well of Ghosts," said Corvik. 'doesn't really sound like a place to take the kids."

"The ancient nomads named it," said Vim, dropping from his saddle to walk beside the sandsteer. "I'd have loved to have seen it as a child."

"I bet you would," said Corvik. "Strange idea of holiday though - plunging into a hole full of spirits."

Up ahead, the sparse vegetation seemed to thicken. Mottled grasses appeared around the mouth of the cave like stubble. Halting the sandsteer, they walked together up to the entrance.

"Well, I'll be damned," said Vim, peering over the jagged edge.

Below, the cave opened into a gigantic cylinder, flooded with light from the blazing star above. Green swathes of spider-like vines festooned the walls, draped thickly over great outcroppings of rock. The air chirruped with the cries of insects, hidden in the moss.

"Tourism's not so mad a prospect now, eh?" said Vim with a grin. "Come on, let's get the gear sorted."

Her hair smelt of apple blossom. Her plum-colored lips were full and smiling. "You need a new job," he said, pinning her arms.

They anchored the winch close to the mouth of the cave, sheltering it beneath an umbrella from the interminable heat. The sandsteer kneeled placidly together nearby, chewing on a few dried roots and watching the two men, their long tales flicking absently.

"I've gotta say, I'm jealous," said Vim. He took a long draught from his canteen. "I might head down myself, after you."

"It'll take some time to zap this one," said Corvik, irritably.

Vim wiped his lips. "You just watch your step down there."

Clipping his helmet under his chin, Corvik slipped the climbing rope into the carabineer on his harness and placed his radio in the holster by his right shoulder. Testing his knot, he walked backwards to the edge of the hole with his weight on the rope.

Vim gave him a final salute as he hopped feet-first over the edge.

He knew the restaurant would save him. She always enjoyed her food.

Corvik looked down between his legs at the cavern beneath him. It was large enough to swallow a Terran skyscraper - at least half a click deep. On his helmet, a Datapod the size of a hen's egg fired laser beams in every direction, measuring the internal volumes and storing the data in a small pack on his waistband. Dust drifted from pock marks in the walls making shadows in the beams.

"How's it looking?" Vim's crackled voice echoed faintly from the radio.

"It's a long way down," said Corvik. "I hope we've got enough slack."

Lifting the tail of the climbing rope, Corvik loosened the hitch in his carabineer and kicked himself out from the wall. The eighty-metre wide opening through which he had entered the cave receded rapidly, yet still allowed enough light for him to see without his lamps. Here, the air was cool and the vegetation was thick. The thud of his feet surprised a pair of small, round-bodied birds, concealed in the foliage. They darted out above the abyss, pin-wheeled in the air and then disappeared, twittering into the light above.

Below, the light was weaker and the vegetation began to thin out.

"How's the sampling coming?" asked Vim.

"Datapod's fine," said Corvik, checking the feed. "I'll get rock and plant samples on the way back up though. I wanna see how deep this thing goes."

On a bare patch of rock between two thick clumps of vines, a large arachnid crouched between dark legs, hissing softly.

"There's a few beasties in here" muttered Corvik to the radio. "The kiddies 'll love it."

She was so cold sometimes.

It was getting gloomy. Corvik flicked on his fluoride lamps and slowed his descent. Around him, life was getting scarce, though he could still sense movement. Things scuttling in the dark, diving for cover in the patchy vines. The air was cooler too, though still faintly humid. It was a musty sort of warmth.

That's not what he meant at all. Just that she could be more considerate, show a little more devotion. She acted like they weren't committed sometimes - like she didn't want other people to know they were in love. No wonder her Academy mates treated him like he was just some friend of hers: cracking their haughty little jokes, always talking shop. Pilots were just glorified bus drivers. He knew her as they never would, though. He'd kept her warm in the moon's winds.

The light was a long way up, a glowing patch in the dark vastness of the cave. The silence was almost complete, disturbed only by the odd scratch of feet, or the distant tweet of a bird in the lighter regions. The walls sparkled in the blue light of his fluoride lamps, scattered by crystalline patches of underground minerals. The air felt damp. There was a trickle of water somewhere.

Facing his lamps downwards, Corvik saw the dark of the cave bottom. He eased himself gently down the last few metres, placing his feet carefully on the slippery wall.

"Tthat's it," he said to the radio. "Ground zero."

"How does she look?" asked Vim. His voice was loud. Corvik turned the volume down.

"Like the worst family holiday you ever had."

His powerful lamps illuminated the cave floor. The light roved over an uneven surface of cold and barren rock, punctuated by the hulks of crumbling boulders, glistening with damp.

"I'm going to take a look around" he said, unclipping his carabineer. The lamps revealed another, smaller cave nearby.

The sunlight streamed in through the open window, across the hair that fell around her shoulders, around her open collar. He wanted her so much just then. He couldn't face what he knew she would say.

Corvik stepped cautiously between the rocks, his lamps casting huge shadows on the walls of the cavern. A few drips echoed loudly somewhere, carrying pristinely in the dark. He shivered with the chill.

The smaller tunnel was enclosed beneath a broken shelf of stone. He climbed over what looked like the remains of a crude rock wall, slipping a few times on the stone. He felt oddly dizzy. The tunnel mouth yawned before him, stalactites and stalagmites forming long, wet teeth. A small pool of water lay close to the entrance.

Fumbling in his pack, he took out a small, glass phial and dropped clumsily to his knees. His hand was shaking, but he managed to dip the phial in the pool of water. A damp breath of air wafted from the interior of the cave.

His lamps must have been struggling because it was pitch-black in the tunnel. The water sparkled like a starry sky.

Corvik blinked and stared into the pool. From the surface, a familiar face stared back up at him, shimmering in the scattered light.

A drip fell loudly nearby. Corvik dropped the phial, steadying himself on a rock. He needed something - something important - for Vim.

The radio was making a racket. What was Vim going on about? He pushed it off his shoulder and leaned forward on his hands. He felt the first tendrils of panic in the back of his mind. But it couldn't be gas; his meter would have alarmed. He looked down to his waistband at his O2 sensor. The screen was blank. The LED wasn't blinking.

The battery. Had he checked the battery? His head felt really woolly. His knees were weak. He'd better try and stand - try and get some cleaner air.

There was a sharp agony in the base of his skull. He was down on the floor, looking up to the glimmer of light at the mouth of the cave. It was all he could see. It glowed yellow, hundreds of metres above, watching him quietly. The world was a creeping darkness. The golden eye winked at him in the silence.

"Goodbye."