The Helix breathed like a living engine, layers of metal and glass sweeping air in measured gulps. Morning came as a sheen across the windward decks — salt on steel, diesel heat, neon curtains flaring like tired banners. Kade Maren felt the city's breath in his teeth as he swung the Skiff's tether loose and dropped between levels. Below him, alleyways stitched steam and laundry; above, a lattice of tramlines cut the sky into slats. He rode the void with practiced fingers, boots finding hooks and joints by memory more than sight.
On the roof where he landed, market noise thinned to a single metallic ratchet. A woman with a child's windbreaker tucked around her waist lifted the crate and grinned like a conspirator. "You got it?" she asked. The crate hummed with a wrapped cell that could keep an oxygen pump running for a week; it was worth a month's wages to people in the lower stacks.
Kade brushed rain from his eyebrow scar. "Duty paid." He handed the crate and caught her wrist for a moment — a habit, a human anchor in a city of machines. The woman eyed his palms. "You're late. These don't wait."
He laughed, safe and small in the flaring light. "Traffic. Sky-rail jammed."
He felt the Skiff under his jacket like an animal. It had been cobbled together from an old courier rig, patched plates, a gyro that coughed but held. People called him reckless on purpose; there were things to be brash about when the alternative was waiting and watching people you loved slow down into quiet failure.
His sister Mara waited in the workshop like a still current. She sat on a crate beneath a patchwork lamp, the respirator's tubing curling across her throat. The inhaler beside her blinked an unimpressive blue; its charge gauge ticked down in tiny, hostile steps. Kade spent his mornings making sure it ticked back up. He opened the crate in the workbench light and set the cell into its cradle. Mara's breath came ungainly, like someone trying to learn rhythm for the first time.
"You look like you ran a race," she said.
"Parcel delivery, heroics, espresso." He twisted a bolt clean and held the crate while the machine drank. Oil and ozone filled the tiny room, familiar and comforting. He watched her cheeks hollow where the air had been thinest.
Beyond the workshop's corrugated door, the Helix thrummed louder, a low spool of sound that threaded up through bones. Kade checked his comm as the feed flickered — maintenance notices, minor reroutes, the kind of background static that kept the city civil. He frowned when the status strip blinked amber: a pressure node listed offline on Level Seven. He frowned again. The node carried redundancy; a single failure didn't show on the public board.
A tremor went through the building like someone had taken a breath longer than they'd allowed themselves. Lights guttered. Somewhere a siren choked and died. The inhaler in Mara's hand hiccupped; its blue light conked out and, for a long second, the workshop smelled like old salt and nothing at all.