The clock on Adeline de Monet's workbench read two in the morning, but she had stopped trusting clocks the moment she began building them.

The gear was wrong. Not catastrophically wrong — not the kind of wrong that would make a layman flinch — but wrong in the way that only she could see, a microscopic deviation in the tooth pitch that would compound itself over ten thousand rotations into something catastrophic. She had recalibrated it four times tonight. Each time, the measurement came back within tolerance. Each time, she set it aside and picked it up again an hour later, certain she had missed something.

The workshop smelled of machine oil and cold copper, the particular combination that had been the atmosphere of her childhood, her education, her entire conscious life. She had grown up on this smell. She had learned to read schematics before she learned to read words. Her father's workshop had been her classroom, and Auguste had been her first teacher — Auguste with his enormous calloused hands and his inexhaustible patience, who had shown her that a gear was not merely a mechanical component but a kind of argument, a proposition about force and direction and the elegant redistribution of energy through space.

Then the smell changed.

It always changed without warning. One moment the workshop was clean copper and oil, and the next there was smoke — not real smoke, nothing that would register on any instrument, nothing that would make her eyes water or her lungs protest. The smoke existed only in the specific neural pathway that connected her olfactory bulb to the part of her brain that stored the night she was ten years old, and it arrived with the reliability of a tide, pulling in whenever she pushed too hard, whenever the work demanded more precision than her hands could currently deliver.

She set the gear down.

This was the protocol she had developed over twelve years: set it down, breathe through her mouth, wait for the phantom scent to subside. It usually took three minutes. Tonight it took seven. She counted them on the clock she did not trust, watching the second hand move with the same mechanical indifference it had always shown, and when the smell finally faded she did not pick the gear up again.

Instead, she crossed the workshop to the shelf where she kept things that were not tools — letters, reference texts, the occasional object that had found its way into her possession by means she could not entirely account for. The newspaper was near the bottom of the stack, folded into quarters, the print slightly smudged from the number of times she had handled it.

She had found it three weeks ago in a secondhand bookshop, tucked between two volumes on hydraulic mechanics as though someone had used it as a bookmark and forgotten it. The article that had caught her eye was not the one she had been looking for. She had been searching for anything relating to volatile compound behavior in closed mechanical systems. What she found instead was a polemic.

*On the Dangerous Irresponsibility of Unregulated Olfactory Experimentation,* by Professor Aldric Voss of the Florentine Academy of Applied Sciences.

She had read it with the detached professional interest she brought to all technical literature, cataloguing the arguments the way she catalogued gear specifications: this one holds, this one doesn't, this one is technically correct but structurally misleading. Voss wrote well. He wrote with the confidence of a man who had never been seriously questioned, and his central argument — that cognitive olfactory research posed unacceptable neurological risks to test subjects and should be prohibited without Academy oversight — was superficially reasonable.

But there were numbers in the article. Specific numbers. Volatility ratios, diffusion coefficients, neural response curves. Numbers that did not read like the work of a man describing someone else's research from a safe theoretical distance. Numbers that read like the work of a man who had *done* the experiments and was now arguing that they should never be done.

She had gone looking for Raymond Vance the next day.

What she found was a reputation. The Academy had no record of him — which was to say, the Academy had taken considerable institutional effort to ensure it had no record of him, which was different. The perfumers' guild knew his name in the way they knew the names of diseases: something to be spoken of in lowered voices, preceded by qualifications. *That* Raymond Vance. The one Voss had written about, though of course Voss had been too careful to use the name directly. The one whose laboratory had been described in three separate formal complaints to the guild council as *a hazard to the cognitive health of the surrounding neighborhood.*

Adeline had also found, through a contact at the city records office who owed her a favor involving a particularly delicate escapement mechanism, the address of the private residence where Raymond Vance conducted his work.

She had spent two days writing the proposal.

It was, she considered, one of the finest documents she had ever produced — and she had produced documents of considerable quality. She had laid out the terms with the precision she brought to mechanical specification: what she needed (controlled-volatility olfactory compounds capable of interacting with her prototype's detection array), what she offered in exchange (precision-machined components accurate to within one-tenth of a millimeter, far beyond the capacity of any standard instrument maker in Florence), and the projected timeline for the collaborative phase of the project. She had included three pages of technical appendices. She had not included anything that could be construed as personal information, emotional context, or a request for anything other than a straightforward commercial transaction.

She had not mentioned Auguste. She had not mentioned the phantom smoke. She had not mentioned that the machine she was building would be the most important thing she had ever made, or that she was building it at least partly because she needed to prove to herself that she was still capable of finishing something.

The proposal was a business document. Business documents did not require the inclusion of wounds.

She folded it now, creased it sharp along the lines she had scored with a bone folder, and slipped it into the inner pocket of her coat. The coat was good wool, dark green, cut to make her look like what she was — a woman of sufficient social standing to be taken seriously in professional contexts — with the added modification of two extra internal pockets she had sewn in herself, deep enough to hold a full set of calipers. She pulled it on over the practical dark dress she wore for late-night work, checked that the pockets were accessible, and went to wake her driver.

The address led her to a district she did not know well — not quite the university quarter, not quite the old merchant streets, somewhere in between, where the buildings had the particular atmosphere of spaces that had once been respectable and had since developed more interesting ideas about themselves. The Vance residence was a tall narrow townhouse with the upper floors dark and the lower floors lit, warm light visible through curtains that had not been fully drawn. The street was empty. The city at two in the morning had retreated into itself, leaving only the cobblestones and the gas lamps and the distant sound of something mechanical running somewhere that it probably shouldn't have been running at this hour.

Adeline paid her driver, told him she would find her own way home, and walked up to the front door.

She knocked.

Nothing.

She knocked again, with more conviction.

Still nothing — but she had the distinct impression that the quality of the silence on the other side of the door had changed. There was a difference between the silence of an empty building and the silence of a building containing a person who had decided not to answer. She had grown up in workshops; she knew how to listen to silence.

She did not knock a third time. She made a fist and hit the door four times in rapid succession, hard enough that her knuckles would remember it tomorrow, and said clearly to the wood: "I know you can hear me. I have a proposal that will interest you professionally. I intend to stand here until you open this door, and I should mention that I am not particularly susceptible to cold or social embarrassment."

A pause. Then, from somewhere behind the door, the sound of something being set down with unnecessary force.

The door opened.

He was taller than she had expected — she was not certain why she had formed an expectation of his height, but she had, and he exceeded it. The lamp behind him in the hallway put his face partly in shadow and lit the edges of him: dark hair, white shirt with the sleeves rolled to the elbow, dark trousers, bare feet on the stone floor as though he had been too occupied to consider shoes. He was looking at her with an expression that was not quite surprise and not quite anything else she had a clean name for. His eyes, where the light caught them, were the color of certain grades of aquamarine glass.

He did not speak.

She thrust the proposal at him.

He took it — she registered the fact that he took it, that his hand came up and accepted the document from hers without any visible deliberation, as though it was simply the logical response to being handed something. His fingers were long, she noticed, and there was a faint discoloration along the edge of his right hand that she recognized as acid exposure.

He looked at the proposal. Then he looked at her. The expression on his face had not changed precisely, but something in the quality of his attention had — it had focused, in the way that a lens focuses when it finds the correct distance from an object.

The silence stretched. She let it. She had negotiated in silence before.

Then he said, in a voice that was lower than she had expected and entirely without inflection: "You've miscalculated the exchange rate, Miss de Monet."

And closed the door.

Adeline stood on the step in the two-in-the-morning quiet of Florence and considered what had just happened.

She had been dismissed before. She had been condescended to, talked over, excluded from rooms and conversations and professional bodies that should have welcomed her. She had been handed back her work with corrections that were wrong. She had been told, in terms ranging from polite to explicit, that the field of precision mechanical engineering was not a suitable occupation for a woman of her social position.

She had never, in all of those interactions, felt this particular thing.

The thing she felt was not anger. It was not humiliation. It was something she had to work to identify, turning it over like an unfamiliar component, checking it against her internal catalogue.

Interest.

He had taken the proposal. He had not handed it back. Behind her, as she stood considering this, she was almost certain she could hear the sound of a page turning.

She looked down at her empty hands.

The door was closed, but she had not heard it lock.