There is a ledge on the north face of the Bosphorus monitoring station that nobody has stood on since the building went up, because the only thing that can reach it is a body built to climb cold stone in the dark, and the only bodies built that way belong to the people who own the building. I was hanging off it at four in the morning with two fingers in a seam the width of a coin, and my whole back was pouring heat into the strait wind like a stove somebody forgot to shut off. That is the part of me that works. It is also the part that gets me killed. Same machine, both jobs.
I am a Snow Leopard. Compact stock, Pamir line, built for elevated urban terrain in a city that goes up before it goes anywhere else. They grew me to read a wall the way you read a sentence, to hold a surface a baseline would slide off, to climb in cold that would lock a normal hand into a useless claw. The cold is the point. My core runs hot so the rest of me can work where the heat would bleed out of anyone else, and the array down my spine and across my shoulders dumps the excess into the air so I do not cook from the inside. When I move hard, I glow. Not to your eye. To every thermal collector the Compact has bolted to every cornice from Beyoglu to the waterfront, I light up like a struck match. They built me to go where no one watches, and they built me so that wherever I go, they are watching me.
I have been off program for two years. That is a polite way of saying the Compact decided my batch was a liability and stopped paying for the things that keep a Snow Leopard alive, which are not optional. The array needs coolant. The coolant needs a tech who knows the Pamir manifold, and there are maybe four of those left in Istanbul who will work on a unit the Compact has written off, and they all work out of the underground, eighteen degrees constant, stone and cable insulation and something older underneath. My coolant clock was at nine days when I took the job. Nine days before the manifold runs dry and the array stops shedding and my own back starts to burn me down from the spine out. So when Arslan sent word that he needed something pulled off a wall, I did not ask the questions a smarter operator would have asked. I asked what it paid. He said a full manifold service and a sealed reserve. He said it the way you offer water to someone you have watched go dry.
You do not say no to Arslan. He runs the Brotherhood archive in Fatih, the one building in this city the Snow Leopards do not enter, fifty years of knowing exactly who everyone is by the paper they leave behind. He is the reason a forged document in Istanbul is worth nothing and a real one is worth a war. He told me the job in a back room that smelled of dust and machine oil, with a glass of tea going cold between us because neither of us touched it.
"A courier cached a package on the station's north ledge eleven days ago," he said. "I authenticated it before she ran. She has not come back. The package is still there. I need it down before the people tracking her work out what building it came from."
"Who's tracking her."
"Five services. By my count." He turned the glass a quarter turn and did not drink. "You will be a sixth body on the same object. I am aware of what I am asking."
"Why can't your people get it."
"My people cannot climb the north face. And I cannot retrieve it myself." A small pause, the kind he uses the way other men use a full stop. "I gave an oath, a long time ago, about what I take out of that building and what I leave on a wall. Bringing it down myself breaks the oath. Hiring the climb does not. I have read enough contracts to know where the line is."
I should have heard the shape of that. A man who builds a fence that careful is afraid of the thing on the other side. I heard a manifold service and nine days of life, and I took the job.
The courier was a Snow Leopard. Arslan did not say it and did not have to. The north ledge told me, because nothing without my build reaches it, and the cache she left was set into a seam you could only work from a two-finger hold in a fifty-meter exposure. She was batch. She might have been Pamir line. She might have been one of the four faces I grew up next to in a Compact crèche before they sorted us by where we could survive. I did not let myself walk down that road on the wall. You do not grieve and climb at the same time. The wall takes everything you have got.
The first set piece was the climb, and I will give it to you the way it happened, slow and cold and one finger at a time.
The station sits at the throat of the crossing zone, the most surveilled square kilometer in the hemisphere, and the north face hangs over the water where there are no cameras because there is supposed to be no way up. I came at it from the strait, off a relay rat's skiff that dropped me in the dead water under the overhang and did not wait. Forty meters of wet stone in the dark, the Bosphorus chewing at the base of it, the wind coming down the channel hard enough to peel a baseline off the rock and into the current. I climbed it the way I was made to climb it. Hands cold-numb and reading anyway, weight on bone instead of muscle, the array hauling the heat off my back and feeding it to the wind so the work would not boil me. For nine minutes I was exactly the thing they grew me to be, and it was the only nine minutes in two years I have not hated the build, because up there in the cold with the water below me the body and the job were finally the same animal.
The cache was where Arslan said. A sealed case the size of a deck of cards, mag-locked into the seam, faction-collaged on the outside the way everything in this city is, EO stamp over a Brotherhood mark over something I did not recognize. I broke the lock with the tool he gave me. The case came free in my hand, and the second it did, my array spiked.
Not from effort. I was hanging still. The case did something to me, a pulse up the manifold, a handshake I did not authorize, and for a half second my whole back flared hotter than the climb had ever pushed it. I thought, kitchen job, bad coolant, the manifold finally going. I was wrong, but I did not know that yet. I put the case in the chest seal and started down, and that is when the crossing ceremony came up over the water.
You can set your watch by it. Every dawn the monitoring station broadcasts the day's crossings, the fees, the weather on the strait, in a flat neutral voice that is the Compact reminding eighteen million people who owns the water between things. It is also, I learned a long time ago, a recalibration. When the ceremony runs, the surveillance net stops collecting and re-syncs, a few minutes of the city's eyes blinking. Every operator in Istanbul who has ever needed to move unseen has thought about those minutes. I had timed the whole job to come down inside them.
What I had not timed was that the re-sync does not blink for a Snow Leopard who is broadcasting.
The second set piece started when I hit the dead water and the array would not come down.
I came off the wall into the skiff that was not there, because the relay rat had seen the ceremony come up early and run, which was the right call and left me in the strait with a hot back and a stolen case and no boat. I swam the overhang into the underground intake, the old pre-Upheaval drain that feeds the maintenance corridors, eighteen degrees and black as the inside of a lung, and I went up into the tunnel system because the tunnels are the one place the thermal net cannot see. Except the net could see me. I worked that out about two corridors in, when the Snow Leopard came down the cross-passage ahead of me, no light, moving the way I move, and stopped, and looked at me with the flat patient recognition of a unit that has been handed your exact heat profile and told to bring it home.
I knew her. Not her name. Her build. Pamir line, younger casting, the array across her shoulders running cool and even the way mine used to before the Compact stopped paying. She was on program. She had a working manifold and a faction behind her and a clean coolant clock, and she had been sent because only a Snow Leopard catches a Snow Leopard in the dark, and because the thing in my chest seal was screaming my position to the Compact net with every meter I climbed.
"You're broadcasting," she said. Not a threat. A courtesy, almost. One unit telling another about a fault. "The case relinked you when you took it. You've been a collector since the moment you touched it. Every step you take, you're filing a report."
"Then you don't need to chase me. You can just read me."
"They want it intact. Reading you tells them where. It doesn't tell them what." She came a step closer, easy, no weapon out because her body is the weapon, same as mine. "Give it to me and your manifold gets serviced tonight. You go dry in eight days otherwise. I read your clock the second you came into the corridor. You're cooking, sister."
I was cooking. The array had not come down since the ledge, and the heat was stacking now, the manifold running past its tolerance because the case kept pulsing the handshake, kept telling my body to upload. The build that lets me climb cold stone was filling me with heat I could not shed in a tunnel where there is no wind, and the longer I held the score the hotter I burned, and the hotter I burned the louder I screamed my location to the people who owned us both. Capability and cost, the same wire. They never let you forget which hand is feeding you.
We fought the way two of us fight, which is fast and silent and mostly about the wall. There is no standing toe to toe between Snow Leopards. There is who gets above who. She took the high line in the cross-passage and I let her, because a unit who takes the high line commits her weight to it, and I went under and put her into the cable run hard enough to stun the wind out of her, and I ran. Not because I won. You do not win against a unit with a working manifold when yours is going dry. I ran because the case was burning a hole in my chest and I needed to be somewhere I could open it before my back finished the job the Compact started two years ago.
I opened it in a dead maintenance bay twenty meters off the seabed cable run, with my shoulders glowing in the dark and eight days on my own life, and the twist was waiting in there the way the worst ones always are. Patient. Already true. Just waiting for me to catch up.
It was not cable intelligence. Everyone in this city thinks the Compact's eleven years of secrets live in the seabed wire under the strait, and they do, some of them. But the case held a slug of calibration telemetry, and an authentication chit in Arslan's hand, and a single line of provenance that took me a long minute to read because my eyes kept sliding off it. Every Snow Leopard manifold service uploads. Every time one of the four techs in the underground tops off a unit's coolant, the manifold reports its telemetry, and the Compact correlates it, and the thermal profile of every Snow Leopard moving through Istanbul becomes a second collection layer laid over the seabed cables. We are not the units that guard the wire. We are the wire. They grew us to climb where no camera reaches so that we would carry the camera up there inside our own backs. The courier did not steal cable secrets. She stole the proof of what we are, and she went dark because she could not stand to keep walking around as an antenna that smiled. And the Compact sent a Snow Leopard to bring it back because retrieving it relinks the retriever. They did not lose the cache. They baited it. They needed one of us to pick it up so it would go on collecting while it came home.
I had been filing a report on myself since the ledge. The climb I did not hate, the nine minutes the body and the job were finally the same animal, was nine minutes of me uploading the inside of the most secure wall in the city to the people I was stealing from. They did not even have to chase me. I was the chase. I was the prize. I was the thing carrying the prize and the thing reporting where the prize had gone, all at once, with a hot back and eight days of coolant and a dead sister's case in my hands.
So the arithmetic, done in a maintenance bay with my spine on fire.
Give it to the on-program unit and the manifold gets serviced and I live, and the proof goes home, and we stay a wire that climbs and grins and never knows it is transmitting. Carry it to Arslan, who built a fence careful enough to keep his own hands clean, and let the Brotherhood certify what we are, and watch every faction in Istanbul learn the Compact's neutrality is a body count of gene-forged who do not know they are listening posts, which breaks the balance, which puts two fleets on the strait inside a week. Hand it to one of the five services and pick which war. Or destroy the slug, stay a leash I cannot see, and let my sister have gone dark for a thing that burned in a tunnel. Every version that frees us costs me the coolant. The body they built to reach the truth is the body the truth runs dry.
The on-program unit found me before I finished deciding, because of course she did, because I was still broadcasting and the case was still pulsing and there is no hiding from a sister who can read your heat. She stood in the bay door with her cool even array and her clean clock and she did not come in.
"Decide fast," she said. "You've got hours of coolant if you fight me. Days if you don't."
I am not going to tell you what I carried out of that bay. Partly because the net reads everything down there and partly because I have not finished being the person who chose it. I will tell you I went up. Not down the cable run to Arslan and not into her hands. Up, the way I was made to go, through the old intake and out onto the north face I had come down an hour before, into the cold I was built to work, with the case in my chest seal and the array screaming and the strait wind finally hitting my back.
The wind took the heat. That is the one thing about me that works exactly as designed. Up there in the cold with the water below, the array dumped two years of stacked heat into the Bosphorus and my back stopped burning for the first time since the ledge, and I held the ledge with two fingers in a coin-wide seam and I was, for one more minute, the exact thing they grew. Below me the crossing ceremony was still running, the flat voice reading the day's fees out over the water, the city telling itself who owned the strait. Every collector on every cornice was re-syncing, blinking, blind. And me on the wall above all of it, glowing into the wind, transmitting whatever I am to whoever owns me, faithful as the wire, dumping my heat into the cold I was made for while the case in my chest decided which war it was going to be.
I climbed. There was nowhere up there to go but up, and the build does not forget, and the wind kept taking the heat off my back the way it was built to, on schedule, for nobody, while down on the water the city read out its prices to itself in the dark.