Ariad doesn't flinch at the hum. She calibrates to it.
We walk her through everything. Juno shows the tag, the lines, and the Anchor Gun. I lay out the fight—divers, knives, the "woke" moment. Mia plays Lark's thermal and the underdeck map we built with breadcrumbs and bad ideas.
Ariad watches the lattice on our visor feed. "Pattern's good," she says again. "Better than good. Whoever did this understands load paths."
"Then why hide it?" Mia asks.
Ariad's shrug is small, academic. "Because they can't get a permit, or won't. Because they don't trust the city. Because they're testing something. Because they're saving us from ourselves."
"Or because they want a lever," I say. "Brace it today, pop it tomorrow."
"That too," Ariad says. "Bring me the sample."
Juno unlocks the hard case and passes the bag. Ariad doesn't open it. She holds it up to the light, thumbs the seam, weighs it like a jeweler.
"Cold reaction," she says. "Condenses when exposed, stops when equilibrated. That's not a polymer I've used."
"Magic?" Mia asks, dry.
Ariad's mouth twitches. "Magic is just math with an attitude. But no, this is chemistry. Maybe guided."
She zips the bag back. "Chain says lab, but the lab won't know what to test for unless you tell them what to test for."
"Kade took custody," Juno says. "We're lucky we got to write the chain."
Ariad's eyes say: lucky isn't the word. She flicks her gaze between planks. "Take me under."
"We just poked the hive," I say.
"So don't poke," she says. "Walk me to the picture. I'll point. You'll listen. Novel arrangement, I know."
Juno doesn't smile. "Clips on," she says.
We go under again. Hum steady; tide low enough to let us breathe. Ariad moves like a rock climber who has read the manual twice. She doesn't reach toward the lattice. She points with her chin.
"Anchor high," she says. "Clip there. There. Stop."
At the fifth pylon, she studies the notch code on the brace spikes. "Three-one-three," she murmurs. "Cute. Old union call sign for [[South Channel Maintenance]]—if you cared about that history."
"You think it's them?" Mia asks.
"I think someone wants someone to think it's them." Ariad's tone is flat. "These spikes match city spec. The pattern does not."
Her hand hovers above the shimmer. "This is bracing in two planes at once. It's not fighting the pier's sway—it's teaching it to sway differently."
"Teaching," Juno repeats.
Ariad tilts her head. "Everything that stands learns. Whoever did this is clever and arrogant. That's a risky combo."
The long line tugs—small, once—like something testing us. The hum does not change.
"Back," Juno says automatically. We give the lattice room, and it ignores us again, like a cat that heard its name.
Mia logs measurements and nods to herself. "If I model this, I need inputs—mass, frequency, dampening."
"Get what you can from Lark and the geophone," Ariad says. "Then we go topside and I write a letter Kade won't read."
"Write it anyway," Juno says.
We climb out. The harbor's brighter; gulls argue; the workday wakes. Our tied diver at the bollard whistles the three-note hum like it's catchy. He shuts up when Ariad looks at him.
"You," she says, not unkind. "Where did you learn to move under structure without touching load braces?"
He tries a smirk. It dies. "Not from you."
"No," Ariad says. "From someone who cares not to die."
Board techs collect him a minute later with a polite "ours." He goes without a fight, eyes on the water, listening.
We sit on deck with our feet over the side. The hum sits in our teeth.
Mia's tablet pings. She frowns. "Permit watch just flagged our tag."
"Flagged how?" Juno asks.
"'Stand down pending review,'" Mia reads. "From Kade's office."
Juno's jaw works. "He already has the sample. He could let us finish the hour."
"He could," Mia says.
My phone buzzes. Unknown: Bring two more lines. No drilling. Noon tide will mask you.
Ariad reads it over my shoulder. "Your ghost is correct about tide masking. Current noise hides vibration signature."
"You're okay with us going back under after a stand-down?" I ask.
"I'm okay with not letting a pier collapse because a man who likes dry shoes wants a cleaner memo," Ariad says.
Juno looks at the placard. Looks at us. "We stay legal until we can't," she says. "Mia, tag extension?"
"I can request," Mia says. "It won't clear before noon."
"Then we go under as civilians," I say.
Juno's look could bend metal. "No."
Ariad raises a hand. "There's a middle: educational walkthrough for contractor assessment. I'm allowed to bring observers."
"Us?" I ask.
"You're my observers," she says. "We don't touch. We don't cut. We look where I point."
Juno hates the bend. She also loves rules that she can repurpose. She nods, once. "We do it your way."
"Good," Ariad says. "Because I have another problem."
We wait.
"Your brace thieves? The foam? The smoke?" she says. "That's theater. The real work here—this lattice—costs money, time, and a quiet yard. I can name three entities in the city who could bankroll it and hide it."
"Name them," Juno says.
Ariad's mouth goes thin. "[[Bayspine Logistics]]. [[South Channel Maintenance]]—if they went rogue. Or the Board itself, off-budget, through a shell you won't find with a map."
Mia winces. "You just sprinkled salt on three open wounds."
"I said could, not did," Ariad says. "Bring me data. I'll cut a name."
"Rao," I say softly.
Juno hears it and doesn't look. "He's a messenger," she says. "Not a banker."
"Messengers pick their routes," Ariad says. "Sometimes their wars."
We spend the next hour loading models into Mia's software. Lark dives for cleaner angles. The geophone sings three notes and a faint fourth when a tug goes by. Ariad hums under her breath, tuning herself to it. The hum shifts in my head from threat to information. I hate that. I also love it.
"Lunch," Mia says at last, eyes grainy. "Then noon crawl."
"Clinic," Juno tells me.
"I'm fine," I lie.
"Clinic," she repeats.
I go, get a wrap, swallow a lecture about overuse and foam residue on blades. When I come back, Kade is at the placard with two men in suits and a smile that isn't.
"Contractor Laghari," he says. "Thank you for your prompt response."
Ariad nods. "Thank you for calling me before anyone cut a brace."
Kade's eyes flick to me. "We're all learning."
He signs the stand-down in the system like a curtain drop. The orange placard blinks from ACTIVE to REVIEW.
"Until my review concludes," he says, "no further under-structure activity."
"We have an educational walkthrough scheduled," Ariad says, blandly.
Kade's smile twitches. "Of course you do."
He leaves us the way he arrived—dry shoes, dry hands, dry words. The hum keeps humming. The city breathes.
Ariad shouldered her pack. "You two nap in shifts," she says to Juno and Mia. "You," she says to me, "eat something that isn't caffeine."
I find a bar in my pocket that tastes like sawdust and sugar. The tide clock crawls toward noon.
Mia stares at the water, then at her phone, then at me. "Tell me you're hearing that fourth note now."
"I am," I say.
"Good," she says. "Because if I'm hallucinating, you're driving."
At 11:57, another text arrives: ANCHORS HUM SHARP AT NOON. COUNT TO THREE BEFORE YOU TOUCH ANYTHING.