The Seawall Exchange

The maintenance corridor let them out through a rusted grille above the freight tram tracks, and then they were running, not sprinting, because sprinting looked like guilt and Harbor Nine's night shift had opinions about guilt. Mara kept the stolen node against her chest like something that might still be breathing. Ilya matched her pace without being asked, wire spool bouncing against his hip, breath coming out in short white flags.

They didn't stop until the tram overpass, three blocks off, where the fog thinned enough to see the water.

"That voice," Ilya said, hands on his knees. "That wasn't Facilities."

"No."

"Facilities doesn't say *maintenance check* like it's daring you to disagree." He straightened, looked back the way they'd come. No lights, no pursuit, just the mural of shipbuilders receding into haze. "You want to tell me what's in the bag, or should I keep guessing?"

"A server. Small one. Fanless, so it doesn't announce itself." Mara crouched against the overpass strut and unzipped the pack far enough to check the unit hadn't cracked. Intact. Warm along one edge, the particular warmth of something that had been working hard right up until she'd ripped it loose. "If I'm lucky, whoever built that closet was too proud of their own cleverness to encrypt the local storage."

"And if you're not lucky?"

"Then I'm a woman with a stolen box and no evidence, explaining herself to Vitriform's lawyers instead of the actual crime."

Ilya considered that with the flat patience of a man who fixed things other people broke and rarely got thanked for it. "Municipal Electrical doesn't pay me enough to get disappeared over a comedy show," he said. "But I've spent four years writing tickets that say *voltage sag, cause unknown* on a system that isn't supposed to sag. So." He shrugged, the gesture of someone already deciding. "Where next?"

Mara pulled up the mirrored capture on her terminal, the one she'd grabbed in the seconds before she killed the screen. Even truncated, it told her enough: the control frames hadn't originated inside that closet. The closet was a relay, a single knuckle in a longer hand. Upstream, the traffic braided back through two hops she recognized and one she didn't, converging on a junction she'd walked past a hundred times without seeing it for what it was.

"The seawall exchange," she said.

Ilya's face did something complicated. "The old telecom hut? By the tide gates?"

"You know it."

"Everyone who works dockside knows it. It's not even locked properly, it's just ugly enough that nobody wants to be the one who breaks in." He glanced at her sideways. "You're going to break in."

"I'm going to *inspect municipal infrastructure*," Mara said. "Very responsibly. In the dark. With someone else's badge."

He laughed once, short and surprised, like the sound had escaped before he'd vetted it. "You're going to get me fired."

"You're going to get yourself fired the first time dispatch reads your ticket queue and notices you've written *voltage sag, cause unknown* forty-one times."

"Forty-three," he said. "I keep a log."

They went the long way, along the tram tracks and then down through the container stacks, because the direct route ran past two Vitriform-leased checkpoints that had never once bothered Mara when she badged through them for a paycheck and would now very much like to ask her questions. The stacks smelled of rust and brine and the specific ozone tang that hung around dockside transformers on humid nights. Somewhere a crane groaned through an automated cycle nobody had scheduled, arm swinging out over black water and back, out and back, hauling nothing.

"That's new," Ilya muttered, watching it.

"Or it's not," Mara said. "Maybe it's been doing that for months and nobody who could stop it was looking."

The tide gates announced themselves before the exchange did: a low mechanical shudder underfoot, water forced through channels never meant to move that fast this far from a storm surge. The gates were meant to hold a rhythm set by moon and weather. What Mara felt through her boot soles was cleaner than that, more deliberate, like something had reached in and started conducting.

The telecom hut crouched at the base of the seawall, gray concrete gone the color of old teeth, its door held shut with a chain that had rusted into decoration rather than security. Ilya produced a bolt cutter from somewhere on his belt with the unbothered efficiency of a man who had opened worse locks for better reasons.

"Municipal Electrical," he said, snapping the chain, "carries excellent tools."

Inside, the hut was one square room stacked floor to low ceiling with patch panels, most of them decades old, cable runs labeled in three different eras of handwriting. But bolted incongruously to the side of an ancient distribution frame sat a newer unit, its case scuffed the same way as the mini-PC from the server closet, connected by a cable that hadn't been there when the original system was installed. Someone had grafted new intent onto old bones.

Mara knelt in front of it and plugged in.

The traffic resolved slower this time, without the panic of a countdown. She watched command frames slide past bound for the tide gates, for a pump station two kilometers south, for something labeled only by a numeric tag she didn't recognize. Underneath the technical noise, buried in a comment field nobody should have bothered reading, sat a string of plaintext: *if you found this, you're already late.*

"Charming," she said.

Ilya leaned over her shoulder, close enough that she felt him go still. "That's not a joke. That's a taunt."

"Same family," Mara said. "Different manners."

She traced the outbound path further and found what she'd been afraid of finding: a scheduled command, timestamped for less than forty minutes out, targeting the tide gate actuators directly. Not the gentle nudges from the server closet. A full manual override, the kind that existed for emergency drainage and nothing else, queued to fire during a routine broadcast window like it was just another punchline.

"If that executes," she said, "the gates open wrong. Not closed when they should close. The harbor floods the low side of the docks at the exact moment high tide peaks."

"How wrong is wrong?"

"Wrong enough that whoever's running this wants people watching the livestream instead of watching the water." She was already pulling tools from her pack, the same multitool that had opened the server closet, a coil of override cable she kept out of habit rather than plan. "I need ten minutes and something to isolate this feed without killing the whole panel. If I cut it clean, they'll know within seconds. If I do it wrong, I could jam the gates in the open position permanently."

"Ten minutes," Ilya repeated, checking his phone. "You want me on lookout, or you want me holding wire?"

"I want you deciding right now whether you're actually in this," Mara said, not looking up from the panel. "Because after tonight, Facilities is going to ask why the chain on this hut is cut, and *load variance* isn't going to cover it."

He was quiet for exactly as long as it took the crane outside to complete another empty swing. Then he crouched beside her, flashlight angled onto the terminal block, gloves already coming off his back pocket.

"Tell me which wire," he said. "I've been writing fiction to my supervisor for four years. Might as well write something true for a change."

Mara traced the override line with one finger, found the junction where the injected command met the legitimate control path, and began, carefully, to make the two signals disagree with each other.

The stream, somewhere above them in the fog, laughed on cue.