The heavy concrete gates of the Mud-Gate Station had slammed shut behind them with a finality that vibrated through the soles of Barnaby Finch’s boots. Now, there was only the mist.

It was not the soft, gray fog of the high peaks, but the heavy, low-lying ion-fog of the Glimmer-Mist Basin. It hung in dense, stagnant pockets, dyed a faint, bruised purple by the raw electrical discharge of the lowland coal-plants. The air tasted of wet copper and scorched iron, so thick with ionized moisture that every breath left a cold, metallic film on the back of the throat. Visibility was barely ten feet. Beyond that pale, violet-tinted curtain lay a desolate wetland of slick clay and black silt-veins, humming with a low-frequency static charge that made the hair on Barnaby’s arms stand on end.

Barnaby stood eight feet above the trembling mud, his lower legs bound tightly into the custom-carved octagonal shafts of his Insulated Oak Stilts. The weight of the one-hundred-pound energy-storage core on his back was a physical, crushing entity. The heavy canvas straps bit deep into his broad, slouched shoulders, compressing his spine and forcing his chin down toward his chest. His knees, stripped of cartilage by fifteen years of heavy-load carrying in the lowland mines, throbbed with a dull, sickening heat. Every muscle in his thighs trembled as they fought to maintain balance on the narrow, eight-foot timber poles.

"Keep your weight centered, Walter," Barnaby rumbled, his voice a low, gravelly rasp that barely carried through the thick fog. "If you let your hips drift, the stilt will catch in the clay, and the ground will have you before you can cry out."

Behind him, "Wet-Foot" Walter stumbled, his cheap, unseasoned ash stilts squelching loudly as they sank into a shallow patch of purple silt. Walter was eighteen, red-faced, with messy blonde hair escaping from a frayed canvas cap. He had joined the crew at the edge of Oakhaven, desperate for a porter’s wage but entirely ignorant of the basin’s lethal physics. His stilts were poorly insulated, the wood grain dry and thirsty, ready to suck in the conductive moisture of the fog.

"I’m trying, Mr. Finch," Walter gasped, his knuckles white as he clutched his cedar guide-staffs. "But these straps are cutting off my circulation. And the ground... it feels like it’s vibrating right through the wood."

"It is vibrating," Clara Thorne said, her voice sharp and cynical from the mist below. She walked on foot along a narrow, elevated granite ledge that bordered the drainage ditch, her grease-stained canvas coat wrapped tightly around her. In her hand, she held her customized brass-and-glass pocket multimeter, its delicate needle flickering erratically. "The ground charge in this sector is sitting at three hundred volts of static potential. If your stilt-tips absorb enough moisture to bridge the gap to your wet socks, Walter, that vibration will turn into a current that will freeze your heart in three seconds. Stop complaining and keep your stride rhythmic."

"She’s right, Walter," Pip whispered. The fourteen-year-old scout glided ahead of them on a pair of light, six-foot bamboo stilts, his movements fluid and silent. He carried their only remaining bundle of dry wool blankets and a single, heavy wooden barrel of pre-industrial pine resin. He paused, leaning his light frame forward against his bamboo staffs as he stared down at the ground. "Look at the metallic grass. See how the blades are bending to the north? The tips are sparking blue. That means there’s an active ground-vein running right through the center of the ditch. We have to swing wide."

Barnaby watched the boy. Pip’s small size and agile balance allowed him to read the terrain with an ease Barnaby’s broken body could never match. But as he looked at Pip’s wiry frame, a cold, familiar knot of guilt tightened in his chest. Thirty years ago, his younger brother Tommy had stood just like that in the rigger yards, optimistic and eager, before the heavy iron girder had slipped from Barnaby’s exhausted grip.

Barnaby closed his eyes for a fraction of a second, forcing the memory back into the dark. He adjusted his grip on his heavy cedar guide-staffs, the wood rough and solid against his calloused palms.

"We use the Three-Point Stilt Stride," Barnaby said, directing his words at Walter. "Watch my rhythm. One stilt anchors. The guide-staffs plant. The second stilt moves. You never have both feet off the ground, and you never let your center of mass drift past the triangle of your support points. Rhythmic. Slow. Solid."

Barnaby set the pace. He swung his right hip, dragging the heavy oak shaft forward through the damp purple fog. The stilt-tip, heavily coated in amber-colored, glass-like pine resin, sank three inches into the wet clay with a soft, sucking sound. He planted his cedar guide-staffs, leaning his torso forward to distribute the core’s massive weight, then swung his left stilt forward.

*Step. Plant. Step.*

It was a slow, agonizingly repetitive dance. The constant weight of the core compressed his vertebrae, sending sharp, shooting pains down his lower back and into his paralyzed knees. His thigh muscles burned, lactic acid building up with every high-stepping stride. But he did not slow down. The damp air was a constant enemy; it clung to the raw oak of his stilts, slowly depositing a fine, conductive layer of water that threatened to bypass their resin insulation.

"The core is getting hotter," Clara warned, walking close to Barnaby’s left stilt. "The micro-fractures in the outer lead shielding are widening from the vibration. The ozone leak is spiking. I can smell it from here."

Barnaby inhaled deeply, utilizing his Ozone-Scenting instinct. The air had changed. Beneath the heavy smell of wet coal ash and sulfur, there was a sharp, biting sweetness—like the scent of a lightning strike just before the thunder cracks. It was the smell of highly concentrated, leaking energy.

"The fog is absorbing the leak," Barnaby rumbled, his eyes scanning the purple gloom. "It’s creating a trail. Anyone with an electrostatic compass will be able to sniff us out from miles away."

"Then we have to keep moving," Clara muttered, her fingers tightening on her multimeter. "If Vanguard's trackers locate this signature, they’ll have our coordinates mapped before we reach the dry ridges."

Suddenly, a sharp, panicked cry cut through the static hum of the basin.

"Mr. Finch! My stilt! It’s stuck!"

Barnaby turned his head, his neck muscles straining under the weight of his pack. Ten feet behind him, Walter had drifted too far to the left, away from the dry path Pip had flagged. His cheap ash stilt had sunk deep into a pocket of wet, purple-tinted clay. In his panic, Walter had forgotten the fundamental rule of the stride; he had pulled his guide-staffs out of the mud, trying to use his hands to balance his upper body. Without the third point of contact, his center of gravity drifted wildly.

"Walter! Don't move!" Pip screamed, trying to turn his light bamboo stilts around in the narrow ditch.

But it was too late. Walter’s right stilt began to tilt at a sharp, unstable angle. The wet clay beneath him bubbled, emitting a high-pitched, vibrating hiss as the ground charge began to ground itself through the uninsulated wood. Faint, purple sparks began to climb up the ash shaft toward his bound boots.

"My leg! I can’t feel my leg!" Walter shrieked, his eyes wide with absolute terror as the residual static charge began to travel through his wet leather bindings.

Barnaby did not hesitate. Despite the grinding agony in his knees, he swung his upper body to the right, shifting the entire one-hundred-pound weight of the core onto his left oak stilt. The wood groaned under the sudden, immense load-bearing limit, the fibers creaking as they absorbed the force of the shift.

Using his cedar guide-staffs to anchor his weight, Barnaby executed a Sudden Pivot. He spun one hundred and eighty degrees on his single, left stilt-tip, his right stilt sweeping wide across the wet clay to clear the active ground-line. The physical strain was immense; his lower back spasmed, and a sharp, blinding pain shot up his spine, but his balance remained unyielding.

He lunged forward, swinging his heavy cedar staff through the purple fog. The curved handle of the staff hooked under the shoulder straps of Walter’s pack frame.

With an explosive heave of his shoulders, Barnaby dragged the terrified rookie backward, wrenching his stuck stilt out of the bubbling clay just as a bright blue ground-spark erupted from the mud-hole, vaporizing a patch of metallic grass where Walter had been standing.

Walter fell backward onto a narrow, dry stone outcrop, his cheap ash stilts clattering against the rock. He was trembling violently, his face pale and slick with sweat, but he was alive.

However, the rescue had come at a severe cost.

As Barnaby completed the pivot, his own right stilt-tip made contact with the edge of the active ground-vein. A bright, blinding blue spark erupted from the clay, striking the oak shaft with a sharp, metallic crack. The residual charge traveled up the wood, but the thick, double-layered oiled leather of his custom boots absorbed the shock, preventing the current from reaching his paralyzed limbs.

But the damage was done. Barnaby looked down, his eyes narrowing. The right stilt-tip was scorched black, the protective amber resin coating completely vaporized by the high-voltage discharge. The raw, unprotected oak beneath was now exposed to the damp purple mist, which was already beginning to seep into the wood grain.

"Your stilt-tip is scorched," Clara gasped, scrambling onto the stone outcrop beside Walter. "The insulation is gone, Barnaby. If you take another step into the wet mud, the wood will act as a direct conductor."

"Get the resin pot," Barnaby rumbled, his voice tight as he fought to suppress the painful muscle spasms in his thighs. He balanced his entire weight on his left, undamaged stilt, leaning heavily against his cedar staffs to keep the one-hundred-pound core from tipping. "We patch it now. Before the damp sets in."

Pip scrambled forward, quickly opening the wooden barrel of pre-industrial pine resin. Clara pulled her portable copper heating iron from her belt, her fingers trembling slightly as she prepared to melt the solid amber blocks.

But as Clara struck her flint to ignite the small, non-sparking charcoal burner, Barnaby suddenly froze.

He raised his head, his chest still heaving from the physical exertion of the pivot. He closed his eyes, his senses tuning out the panic of the rookies and the hiss of the heating iron. He focused entirely on the high-frequency hum of his stilt-shafts and the scent of the air.

The metallic smell of ozone had spiked, but it was not coming from his leaking core. It was a cold, sharp scent, carrying the distinct, oily smell of coal-smoke and hot iron.

And then, he felt it.

It was a low, rhythmic vibration traveling through the deep earth, felt not through his ears, but as a high-frequency thrumming in the soles of his boots against the wooden stilt-brackets. It was the heavy, synchronized thud of massive rubber treads grinding through the wet silt-flats.

Miles away, in the deeper sectors of the basin, "Volt-Hunter" Vance stood on the high platform of a Vanguard patrol tower, his lean face illuminated by the green glow of his steam-powered electrostatic compass. The delicate vacuum tube at the center of the device pulsed with a bright, rhythmic blue light, its needle locking onto a unique, leaking energy signature that cut through the purple fog like a beacon.

Vance reached down, adjusting the brass dials on his leather tracker’s coat. "We have the signature," he muttered into his receiver, his voice cold and professional. "The core is active. It’s moving north-northwest through the lower basin. Alert the enforcers."

Back on the stone outcrop, the thrumming grew louder. It was a distant, rhythmic thrumming that shook the wet purple clay of the basin, sending small ripples through the conductive saltwater channels.

Barnaby opened his eyes, his gaze locking onto the dense, impenetrable curtain of purple mist behind them.

"Brand’s crawler," Barnaby rumbled, his hand tightening on his cedar guide-staff until his knuckles turned white. "They’ve entered the basin. They’re tracking our scent."