A figure bolted out of the opening, cloak flying out behind him. A too-familiar radiance filled the doorway and in the cold sepulchral glare she saw the man hurl himself into the cockpit of the Midge and slam the door shut. Cold oily light spilled out onto the dust, lapping around splintered sandstone and granite. Both engines flared bright with exhaust and the Midge leapt forward, sand spewing away from the wheels.

Gretchen pulled back gently on the control yoke and Gagarin soared up into the dark, constricted sky. The overhanging cliffs on either side rushed in, but she adjusted nimbly, sweat beading in the hollow of her neck, sending the ultralight dancing higher. Through the transparent panel under her feet, Anderssen saw the other Midge dart up the canyon, lifting off only meters ahead of the advancing radiant tide.

The cold light cut off – a shutter slammed on an empty window – and Gretchen felt the air in the canyon heave with a sudden, sharp blast. A cloud of black smoke jetted from the tunnel mouth, drowning the queer light, and Hummingbird's Midge wobbled in flight as a shockwave rolled past.

Gretchen wrenched her attention back to the business of flying, narrowly dodging the Gagarin around a jutting outcropping. The airframe groaned, complaining at such rough handling, but the Midge swept past the obstacle and soared on down the canyon. Below her, Gretchen was peripherally aware of Hummingbird's ultralight straining to catch up.

The canyon behind both aircraft filled with a black, turgid cloud of dust and ash. The cliff-face above the tunnel shuddered, still rocked by the violence of the explosion and then – with majestic, slow grace – splintered away from the core of the mountain and thundered down into the canyon. More dust, ash and grit roared up with a flat, massive thump.

Gretchen heard the blow, and grinned tightly, fingers light on the stick. This business of flying at night, even with goggles, radar and the strobe-white glare of the wing lights was tricky business. I hope that's the end of the nasty dirty color, she thought peripherally, some tiny corner of her mind pleased to see something which had threatened her destroyed.

The odometer on the control panel began to count the kilometers as they flew on into the night. There was a long way to go before dawn roused the slot canyon to near-supersonic violence.

Behind the massive barrier of the Escarpment, dawn was much delayed. When the clear, hot light of the Ephesian primary finally pierced the canopy of the Gagarin, both ultralights were far out over the western desert. Hummingbird's Midge was only a hundred meters to starboard, easily keeping pace in the cool, thick morning air.

Gretchen clicked local comm open. "Shall we land?"

She hadn't heard a peep from the nauallis since they'd left the canyon. Watching the roseate glow of dawn creeping across the rumpled, barren landscape below them was interesting enough without his company. They had passed over a broad valley filled with pipeflowers in the predawn hours and Gretchen had been very glad the spindly, fluted organisms were quiescent after sunset. There had been places – deep ravines or defiles in the broken land – where jeweled lights had gleamed in the ebon blanket of night.

The palaces of the fairy queen, she thought, staring down at the traceries and cobwebs of trapped, frozen light passing below her. And by day? Nothing, only desolation and lifeless stone. I wonder if Sinclair has dared see the desert by night, her veils drawn aside…

"Are you tired?" Hummingbird's voice sounded thick and muzzy.

"Have you been sleeping?" Gretchen frowned across the distance between the two aircraft. She couldn't make out more of the nauallis than the outline of his kaffiyeh in the close confines of the Midge cockpit. "We should set down before the air grows too thin – we need to conserve fuel after burning so much to reach the summit of Prion."

"Understood," he said, voice clearer. She could see him shift in his shockchair. "Pick a suitable location."

He was sleeping, she thought wryly, glancing at the autopilot display on her panel. He slaved his Midge to Gagarin and tagged along like my little brother at a Twelfth Night party.

Scratching a sore on her jaw where the rebreather strap was starting to wear, Gretchen began to scan the radar map of the land ahead, searching for a cave or ridge or anything which would let them escape the heat and brilliance of the sun. I wonder what our trusty guide has to say.

She punched up the travel maps in Russovsky's log and began going through the notes, wondering where the geologist had landed on her circumnavigation of the globe. After twenty minutes of keeping one eye on the horizon and one on the maps, she opened the local channel again.

"There's a place ahead," Gretchen said, squinting at the lumpish dun-colored landscape. "Russovsky calls it Camp Six – a canyon, an overhang big enough to pull a Midge into the shade – she'd stayed there two, three times. About an hour, hour and a half."

The nauallis responded with a grunt and Anderssen was disgusted to see him lean back in his shockchair, apparently asleep again.

The full weight of day was upon the land, flattening every color and detail to burnt brass. Russovsky's overhang stood in the curve of a long, S-shaped ravine where hundreds of tons of sandstone had crumbled away, leaving a fan-shaped talus slope. Gretchen climbed among the upper rocks, laboring to breathe as she pulled herself up onto a tilted, rectangular boulder. She stood up and the roof of the raw amphitheater was within arm's reach.

Curious, she scanned through a variety of wavelengths visible in her goggles. From below, where the two Midge s stood in partial shade and Hummingbird was puttering around the camp, setting up the tent and making a desultory attempt at breakfast, she'd seen a faint pattern on this rock, something like interlocking arcs or circles.

Close up she didn't see anything unusual, which Gretchen admitted to herself was par for the course. Rock fractures or mineral deposits… A little miffed at getting excited over nothing she looked around, taking in the barren, sun-blasted landscape. The ravine was very peculiar-looking to her eye – no water had run on the surface of Ephesus III for millions of years, so the bottom of the "canyon" was jagged and littered with fragile-looking debris. A similar canyon on Earth or Ugarit would have been washed clean, worn down, abraded by flash floods or even a running stream. But there was nothing like that here, only the evidence of constant wind.

No litter in the shade, she thought, left by those who passed this way before. No broken bits of pottery, flaked stone tools, arrowheads. No detritus of bones from the kill, cast aside from where a fire burned against the stone, leaving soot buried deep in every crevice. Nothing but the spine of the world, open, exposed, left out to bleach in the sun.…Gretchen thought she understood why Russovsky had spent so muchtime alone in the wasteland, drifting on the currents of the air, floating high in the sky in her Midge.

"Is there lunch yet?" Anderssen began picking her way down through the broken, eggshell-like slabs of sandstone.

"Yes," Hummingbird said in a grumpy voice.

Gretchen sighed, but said nothing, preparing herself for threesquares straight from the tube.

She was not disappointed, though the Mйxica had scrounged up some flavored tea. Still, protein paste was protein paste, even if the taste approximated the reddish dust covering every surface in all directions. Gretchen watched Hummingbird eat, making sure he finished his daily ration and drank all his tea. When the nauallis was done, she lifted her chin questioningly.