Tracking Thermal Winds

Can three riders navigate the High-Sulphur terraces without snapping their boards on concealed slate teeth? Suzume crouched at the rim of the High-Sulphur terraces, testing the biting yellow updraft against the palm of her calloused hand. She needed an unbroken line through the choking fumes to reach the tournament register before sundown, and she had no intention of letting two reckless lowlanders crack their hulls on the jagged terrace steps before they even paid their tribute.

Behind her, Ryoma leaned on his slate board, scraping a thumb across the charred heel binding he had scorched in the sprint. The board's tail still carried a hairline fracture from the scree drop, weeping gray stone dust whenever he shifted his weight. Kotaro stood two paces back, adjusting the heavy resonant-wood drums lashed across his broad chest, his pumice bangles clinking with every breath.

"Wind smells like rotten eggs and bad decisions," Ryoma said, flashing a soot-streaked grin. "Which ridge are we dropping?"

"Neither," Suzume said, not looking back. "You drop on either side and the sulfur crust drinks your board down to the binding straps. Follow my line, match my lean, and keep your mouth shut so your teeth don't yellow."

She drew a micro-knapped flint dart from the bandolier across her chest, seating it into the vulcanized hide pocket of her sling. The terraces fell away below them in tiered, sickly ochre shelves, steaming with vents that spat pale gas every few seconds. Most skimmers saw only blinding haze down this slope. Suzume saw the thermal ribs—narrow corridors of rising heat where the gas column carried enough lift to float a slate deck across the crumbly scree.

She nudged her board over the lip.

The polished underside struck the crusted dust with a sharp hiss. Heat bit through the thick hide soles of her boots as the slope took her weight.

Ember-orange script flickered in the corner of her vision, sharpening the air currents into faint amber ribbons. To her left, the main chute dropped into a bowl of bubbling sulfur slurry. To her right lay the narrow spine that led to the registrar's gate.

Ryoma dropped into the chute right behind her, his board carving an aggressive arc that threw up a rooster-tail of yellow grit. "Plenty of friction here! The gauge is climbing!"

"Control your drift, cinder-rat," Suzume snapped over her shoulder. "The shelf under your right rail is hollow crust. Shave two inches left or you'll find out how deep the slurry goes."

Ryoma leaned hard, his slate scraping the rock with a shrill squeal as he tucked into her wake. Kotaro followed with a booming laugh, his wider board rumbling across the shale like a rolling boulder.

Suzume's eyes narrowed. Fifty paces ahead, where the amber thermal ribbon banked around a basalt pillar, the ash looked wrong.

Normal volcanic wind swept the dust in rippling ripples, but three distinct patches lay dead flat, grayed over with fresh pumice. Just beneath that powdered crust, faint triangular shadows caught the low glare of the vents.

Barbed slate caltrops.

They were ground from dense, brittle hornfels, anchored to the bed by braided sinew pegs. If a rider hit them at thirty miles an hour, the teeth would shear through slate decks, shatter timber bindings, and pitch the rider headfirst into the boiling crust.

"Brake!" Suzume shouted.

"Braking kills the heat counter!" Ryoma shouted back, leaning into the curve.

"Brake or lose your feet, idiot!"

She whipped her sling overhead. The vulcanized hide cord hummed, catching the rising draft. Her gaze locked on the lead peg anchoring the nearest cluster. She calculated the drop, the crosswind shear from the sulfur chimney, and released.

The flint dart whistled through the yellow fog.

Crack.

The micro-knapped head struck the anchor peg flush, severing the dried sinew cord. The tensioned trap sprang prematurely, flinging three jagged slate spikes into the empty air where they shattered harmlessly against the basalt pillar.

Suzume did not pause. She loaded a second dart, spun her weight on her back heel, and whipped another shot into the second anchor just as Ryoma's board skidded into view. The second trap exploded upward in a shower of splintered stone, the shards skittering wide across the slope.

Ryoma cut hard to the right, his board's chipped tail clearing the newly revealed spike bed by less than a handspan. He slid to a halt beside her in a cloud of smoking dust, his eyes wide.

"Those aren't natural formations," Ryoma muttered, staring at the row of dark, serrated slate wedges still bedded in the ash.

"Terrace champion work," Suzume said, stepping off her board and kicking one of the exposed wedges free with the toe of her boot. She picked up the jagged tooth, turning it in her hand. The base was marked with a stamped spiral—the personal hallmark of Torano's personal foundry. "Barbed hornfels, preset to catch lowlander boards. Torano didn't just proclaim rules at the ridge. He salted the qualifying chutes."

The ember-orange characters settled into her status log with a clean chiming note. Suzume tossed the barbed slate wedge to Ryoma, who caught it with a grim expression.

"We keep that," Ryoma said, tucking the spike into his sash beside the glowing fire-tempered glass nodule. "The clan arbiters might want to see how the terrace scion runs his trials."

"They will call it course maintenance unless we bring half a bushel of them," Suzume retorted, though she tucked two more severed spikes into her quiver. "And if you keep drifting like a blind scavenger, we won't live to hand them over."

Kotaro pulled up beside them, his heavy board grinding across the crust before coming to a firm stop. He wiped yellow powder from his nose with a thick forearm. "Spikes in the chute? Dirty pool. A real skimmer takes a corner on balance, not on buried stone."

"He doesn't want competition at the register," Suzume said, scanning the lower terraces where the smoke thinned toward the basin gate. "The path ahead is choked with loose pumice. We have five hundred yards of dead flat gravel before the next thermal ridge. Without updraft or slope, we lose momentum."

Kotaro grinned, adjusting the rawhide straps of his resonant-wood drum. "Loss of momentum is an insult to the earth. Watch the master work."

"Kotaro, don't," Suzume began, raising a hand.

He struck the drumhead with his bare palm.

BOOM.

A low, concussive wave rippled out from the resonant wood. The acoustic shock rolled through the ground, vibrating the loose gravel and pulverizing the small pumice chunks into fine, slippery silt that reduced surface friction to near zero.

"See?" Kotaro bellowed proudly. "Acoustic lubrication! The scree is soft as grease!"

Before Suzume could curse him, the deep reverberation did not stop at the surface scree. It sank deeper, finding a hollow pocket beneath the shelf.

A sharp, hollow groan echoed from the belly of the terrace.

The pale crust under their feet began to spiderweb with bright orange fissures. A foul blast of sulfur steam vented from a dozen tiny perforations, and the stone beneath their slate decks dropped two inches with a sickening crunch.

Suzume looked down as the ground turned into a sagging, trembling honeycomb of boiling rock.

"Three out of ten for rhythm," Suzume said between gritted teeth, locking her boots into her bindings. "Ten out of ten for waking the mountain."