Cain sat behind the long table like a judge in a ruined church, hands folded, the red light of the lab painting his knuckles a slow, deliberate color. When he spoke, it was with the same level calm he used when he told men they'd be promoted or buried.
"Dagger." He didn't rise. "You've earned more than dirt here. I want you overseeing Project Meret."
The words hit like a closing door. I'd expected field tasks, retrievals, tests of obedience, not command. The air in the chamber felt thinner when Cain said it again, slower: "Oversee it."
"You want me in charge of their people?" I asked. My voice came out behind the mask, low and flat.
Cain's smile was a paper thing. "Koren tries. He tinkers. He lacks the necessary arrogance to finish what Meret started. He's not Meret. He'll never be Meret. You, however, you carry both a medic's patience and a soldier's efficiency. You'll make the work useful." He leaned forward, the light cutting across his face. "Fix the mistakes. Guide the scientist. Make us safe."
Make us safe. The irony was bitter.
Hours later, alone in a small observation room with a bank of warm monitors, I opened the research files Koren had handed off in a hand that shook with guilt. Schematics, trial notes, autopsy sketches, pages of half-solutions and desperate notes in Meret's hand, then Koren's frantic attempts to force the equations to behave. It read like someone trying to compose music out of broken glass.
I started at the beginning and traced the mistakes like a surgeon following a vein.
Meret's original notes had ambition and restraint. She wanted responsive biology that healed; a scaffold that could read a wound and reorganize. Koren had misread that restraint as a bug, not a feature. He had amplified reaction rates, suppressed feedback loops, and trimmed safety margins until the system responded faster than the host's ethics could respond with judgment.
The first problem leapt off the page: the serum adapted continuously without a natural termination. There was no "done" state, only "iterate." The second was worse: it recorded and replayed tissue solutions as templates. If a subject endured a trauma, the serum catalogued that adaptation and applied it wholesale wherever similar stressors appeared. In short: the body would learn, and then keep learning, until there was nothing left of its original shape or restraint.
If Talon perfected that, they wouldn't have soldiers. They'd have emergent systems that rewired themselves in response to everything they encountered. Unpredictable. Undefendable. In practice, unstoppable.
I felt the floor tilt a degree I couldn't afford. Meret's dream, healing without limits, would became a machine that would eat humanity for the prize of survival.
Once I understood this, I moved like a ghost through the lab. Koren read my face the way a man reads a weather chart: for signs of storm. He flinched when I asked about the feed rates. He stuttered when I suggested a variant that favored polymeric scaffolding over rapid protein synthesis. He trusted me because I wore the mask, because Cain had spoken my worth aloud, because my hands had stitched more men back together than he'd held.
I began steering him.
Not with lecture; with coaxing questions, with a hand on his shoulder, a direction suggested as if it were his idea. "Have you considered a termination feedback?" I'd say, casually. "A signal that tells the scaffold to rest." He'd frown, run tests, and then come back to me with a small victory. "Yes. Maybe." We'd tighten parameters. He'd note the delta. The work moved forward on a line I'd traced.
But while I taught him how to make the serum behave, I worked on something else in secret.
You can't stop a force by arguing with it. You have to put a limit into the engine, some built-in reset no one could remove without undoing the whole design. I started to design a failsafe that would not be an instruction manual anyone could read and use. I kept it at the level of architecture and signature: a molecular flag woven into the serum's operating matrix, a non-native code the serum would accept only when its host's physiology responded to a bespoke trigger.
In the lab, it looked like a keyhole: an intentionally inert motif in the program that would accept a specific, externally applied "key." That key would not be a chemical anyone could spray into a crowd. It would have to be something that wasn't common. When the key activated, the scaffold would terminate, collapse, and the serum's adaptive processes would stop within milliseconds. The subject would go still. The adaptation would die where it stood.
It was necessary. If Talon had power, they would weaponize the serum. There was no guarantee that these subjects under the influence of the serum wouldn't adapt to whatever method Talon was using to control them. If Overwatch could ever be compelled to act, there had to be a way to undo it without playing god in reverse.
I embedded the flag into a line of code Koren would accept as a stability patch: plausible, modest, protective against runaway reactions. He signed it and I watched him sleep that night with exhaustion carved into his face, thinking he'd done the right thing. He had. But he had no idea of the door I'd left open beneath it.
Cain noticed the change in the lab the way a predator notices a new scent. He called me to the chamber and watched me oversee a live trial: a subject who'd reached the point of systemic rewrite, an animal of skin and learned armor that had survived two simulated traumas and rebuilt itself between each.
"Do you trust your hand?" Cain asked, voice casual.
I answered as Dagger. "I trust science. I trust refinement."
"Meret would have wanted this," he said softly.
"I think Meret wanted to heal people," I said. "Not create doctrine."
Cain's lips tightened. "Words. Useful for preaching. Less useful for action. We have a window; we must "
When the trial began, I observed, logged, and guided. Koren followed my instructions more than his instincts, correcting the feedback constants I'd suggested. The subject adapted — at a slower, more watchful pace. It remained recognizably human longer; patterns emerged that suggested the algorithm could be taught restraint.
But restraint could be ripped out like a seam.
After the trial ended and the subject had been sedated, Cain summoned me privately.
"You're doing well," he said. "You've done what I asked."
"And you wanted me to," I answered.
"Good." He paused then, face unreadable. "You'll report directly to me now. The board wants accelerated results. We want the next batch ready in two months."
Two months. In the lab, that meant the difference between control and calamity.
"I'll need more resources," I said. "And time to validate both ethically and scientifically."
Cain's eyes narrowed. "Ethics are an indulgence we don't afford. Results are what move the world."
I kept my silence. His world and mine had never been the same thing.
At night, when the lab quieted and the pumps slowed their breath, I worked on the failsafe code. It lived as a hidden scaffold inside a hidden scaffold, something Koren would see as a benign calibration patch and Cain would see as successful optimization. Next chance I got, I would have to tip Adawe and Gabriel off of what the trigger was.
There was a cost. Embedding the failsafe made the system, in a manner of speech, know itself. It would always carry that flag. If Talon ever stripped it out, they'd need to rewrite the entire program. It was a lock with no easy pick.
I tested the theory on tissue samples, then inert matrices, never on a living subject. That was a line I tried to respect, because even when you walk through darkness, you don't want to learn how comfortable you are with the knife.
Everytime I signed a line in Koren's ledger, every time Cain praised the work and suggested we accelerate the schedule, I felt the weight of the red thread I'd sewn into the code. The project moved forward, but under my hands it had a death. A last, bitter mercy.
When I finally presented the next trial's parameters to Cain, he read them once, twice, then smiled the smile of a man counting coins.
"Excellent," he said. "You have a surgeon's hand, and a blacksmith's will. Continue."
I left the lab with Koren's exhausted thanks clinging to me like dust. Adawe's cipher would be my only way to articulate the fail-safe to Reyes without telling the man aboveground what I'd done. He would know enough to understand and to use it if the time came.
On the walk back through the tunnels, the lights passed in slow rhythm. Above me, a city moved through its small, human problems: traffic, charity drives, the banal rhythm of lives that had not been rewritten.
Below, something dangerous learned how to be better.
I thought of Meret and her notebooks of restrained ambition. I thought of the subjects in their pods, shifting flesh into answers no one ordered them to find. I thought of Adawe's conditions, of her warning that if I stepped over a line no one would come for me.
Then I thought of the trigger, so small that they were going to miss it and the promise it represented: that if Meret's dream became Talon's weapon, there would be one way to stop it, held by those I'd trusted above, that could stop it. I had given Talon the future they wanted. Quietly, in a way only I could, I had given Overwatch the one tool they would need to cut that future from the world.
Between the two of them I stood, a surgeon with a scalpel and a saboteur with a secret. Neither side had my whole story, and perhaps that was the only advantage I had left.