He did not leave.

That was the first thing she noted — the door remained open, and he remained in front of it, and the silence between them had shifted from the silence of assessment into something with more texture. A thinking silence. The kind that meant she had said something that required processing.

Irene waited.

She was good at waiting. Three years of fieldwork had taught her that silence was not empty — silence was where people revealed themselves, in the microexpressions they allowed when they thought no one was cataloguing them, in the direction their eyes moved, in the way their breathing changed. She had built entire psychological profiles on the evidence of a forty-second silence.

Gavin Blackthorn did not reveal much.

His face was — she searched for the precise clinical term and settled on controlled. Not blank. Blank implied absence; this was the opposite of absence. This was presence so tightly managed it had achieved the appearance of neutrality. She had seen it before in people who had spent years in high-stakes environments where the cost of an unguarded expression was measurable. Soldiers. Surgeons. Long-term undercover operatives.

And, apparently, judges in empires with crystal-powered gas lamps.

"You have evidence," he said. Not a question. A re-statement, the way a person repeated something back when they were deciding whether to believe it.

"I have a preliminary reconstruction of the toxicological timeline," she said. "Which is not the same thing as evidence. It is a framework that evidence could be fitted to. Or not fitted to, which would be equally useful."

The amber eye moved. A fraction of a degree — a recalibration she was beginning to recognize as his tell for encountering something that did not fit his existing model of the situation.

"Most people in your position," he said, "would be arguing their innocence."

"Most people in my position are not in a position to do anything more useful than that," she said. "I am."

Another silence. This one had a different quality — not processing, but deciding. She watched the line of his shoulders, the set of his jaw. He was weighing something, and whatever scale he was using, she did not yet know its calibration.

Then he stepped inside.

He did not bring the door fully closed behind him — left it an inch ajar, she noted, which was either procedural or a statement, and she was not yet sure which. He moved to the center of the room with the same economy she had already catalogued and stopped approximately two meters from her, which was close enough to conduct a conversation and far enough to maintain every layer of professional distance the situation demanded.

He did not offer to sit. There was nothing to sit on.

"Five minutes," he said.

Irene did not waste any of them.

She raised her right hand and let the Black Dossier interface surface — the faint crimson lattice of it casting its particular light across the obsidian walls, geometric lines intersecting at evidence nodes that only she could see fully. She was aware of him watching the gesture. She was aware that to him it likely looked like nothing more than a woman moving her hand through empty air in a precise pattern, and she did not explain it. Explanations would come later, if there was a later. For now she needed the data.

The toxicology entry was incomplete — three seconds of reconstructed chemical signature, a degradation curve, an estimated onset window. It was enough.

"The compound used to poison the Crown Prince has a minimum onset time of two hours," she said. "That is not an estimate — that is a biochemical property of the substance. The crystalline alkaloid structure requires a minimum of one hundred and twenty minutes to achieve lethal blood concentration in an adult male of average weight, accounting for metabolic variation." She paused. "Your Crown Prince was how old?"

A beat. "Twenty-six."

"Average build?"

His jaw tightened slightly. "Yes."

"Then the minimum is two hours, and the realistic window given his likely metabolic profile is closer to two and a half. Which means" — she moved her finger along the Dossier's invisible timeline — "that the substance had to have been introduced to whatever he consumed no later than two and a half hours before the first symptom appeared. Probably earlier."

She looked at him directly. "What time did he die?"

Another pause. He was deciding, she knew — deciding whether giving her this information was providing a tool to a guilty woman or verifying the reconstruction of an innocent one. She watched him decide.

"The Crown Prince collapsed at the fifth evening bell," he said. "He was pronounced dead one hour later."

She had not known what an evening bell was twelve hours ago. The Dossier had been helpful about that. "Which places the introduction of the poison at the third evening bell or earlier." She looked at him. "Your witness testified that she saw me place an object in the Crown Prince's goblet at the third evening bell."

"That is correct."

"That is impossible."

The blue eye brightened fractionally. She was beginning to understand what that meant — it meant he was paying the particular kind of attention that his instrument paid when it was running at full sensitivity.

"The third evening bell," she said, "is the earliest possible window. If your witness is correct about the time, then whoever placed the poison did so with almost no margin for error — a single glass, a precise dosage, the exact minimum required. That level of precision is not consistent with a crime of opportunity or a crime of passion." She held his gaze. "It is consistent with a crime that was planned, rehearsed, and executed by someone with a detailed knowledge of the compound's properties."

She let that sit for a moment.

"I am a nobleman's daughter who has spent the last six months in the capital attending social functions," she said. "I do not have a detailed knowledge of crystalline alkaloid pharmacokinetics. The person who committed this crime does."

The silence that followed was not a thinking silence or a deciding silence. It was — she identified it with some precision — the silence of a person encountering a piece of evidence that did not fit the case they had built, and being honest enough with themselves to register the fact.

Gavin Blackthorn was, whatever else he was, honest with himself. She filed that as important.

"You were in custody from the second evening bell," he said.

"I was." She watched him process this. "Which means that even if your witness is correct about the time — and I do not believe she is, but even if she were — there is a window problem. A minimum two-hour onset, a third-bell placement, a fifth-bell collapse. The placement and the timeline are consistent. But the placement and my custody are not."

He was very still now. The kind of still that was not the absence of movement but the presence of intense internal activity.

"That still leaves the first and second bells," he said. "The goblet could have been tampered with earlier."

"Yes," she agreed. "Which means your witness is either wrong about the time, or lying about what she saw, or describing a different event entirely and it has been misattributed." She tilted her head. "Any of those possibilities interests me. Which one interests you?"

His jaw did something — a fractional movement, less than a millimeter, in the direction that might in a less controlled face have become an expression. She catalogued it without reacting to it.

"The report," he said.

She did not understand for a moment.

He reached into the interior of his coat — dark wool, she noted, extraordinarily fine, the kind of fabric that was woven rather than constructed, the kind that required someone to care very specifically about the difference — and withdrew a folded paper. He did not cross the distance between them to hand it to her. He bent down, placed it on the stone floor, and straightened.

The space between them was perhaps one and a half meters. He had not closed it.

She crossed it, picked up the paper, stepped back. She was aware that she had moved toward him and that he had not moved toward her and that the asymmetry of it was deliberate on both their parts, for different reasons. She did not look up to confirm this. She read the report.

It was a partial toxicology summary — formal, precise, the language of someone who knew what they were documenting and had documented many such things before. Symptom onset: fifth bell, eight minutes. Prior to onset: consumption of wine at banquet, estimated one to two goblets over the course of the evening. Crown Prince's known medical history: no relevant conditions. Cause of death: respiratory failure secondary to crystalline alkaloid poisoning.

She read it twice. Then she folded it along its original creases and held it back out toward him.

He crossed the distance to take it — which meant, she noted, that he had chosen to close the space rather than repeat the floor maneuver. An incremental adjustment. She did not comment on it.

"The timeline is consistent with what I described," she said.

"I noticed."

"Your witness is describing something that either did not happen or did not happen the way she says it happened."

"The witness has no apparent motivation to fabricate."

"Witnesses with no apparent motivation to fabricate," she said, "are sometimes the most interesting ones." She met his gaze directly. "Because it means either they are telling the truth as they experienced it, in which case their perception was manipulated, or they are lying, in which case someone went to considerable effort to construct a lie from a person who appears to have no reason to tell one." She paused. "Either of those things would require resources. Planning. The same level of precision as the poisoning itself."

He was looking at her the way he had looked at her in the doorway the night before — with the assessment fully engaged, the instrument running — and she could see him not finding what he was looking for, and she could see what that cost him in the tightness around the corners of those mismatched eyes.

"You are either very innocent," he said, "or very good."

"Those are not mutually exclusive," she said.

For a long moment, neither of them said anything.

Then: "Sleep. There will be more questions in the morning."

He turned toward the door. She watched the breadth of his shoulders, the precise economy of the turn, the way the obsidian crystal light caught the silver at his collar and made something cold look, briefly, like something else.

"The witness," she said to his back. "What is her name?"

He did not turn around. "That is not information I am providing to you."

"I am not asking so that I can suborn her," she said. "I am asking because the name will tell me something about her social position, her relationship to the Crown Prince, and the likelihood that she is operating independently or at someone else's direction." A pause. "You can decline to answer. But you should know that I will reconstruct it from other sources if you do."

The door was open. He was in the doorframe. One more step and he would be through it.

He stopped.

"Lady Maren Ashveil," he said. "Lady-in-waiting to the late Crown Princess."

He left.

The door locked.

Irene stood in the middle of the cell and looked at the Dossier's evidence map and thought: Lady-in-waiting to the late Crown Princess. Which meant access to the Prince's household. Which meant visibility at every formal event. Which meant the capacity to observe, to report, to be positioned exactly where someone with a plan would need a pair of eyes.

The Dossier updated with quiet efficiency:

[WITNESS: LADY MAREN ASHVEIL — FLAGGED FOR SECONDARY ANALYSIS] [SOCIAL POSITION: HOUSEHOLD STAFF, IMPERIAL INNER CIRCLE] [CASE PROGRESS: 12%]

Above her, the footsteps resumed.

She sat down on the cold floor and began to build a profile of a woman she had never met, in a world she had arrived in forty-eight hours ago, for a murder she had not committed.

The work, at least, she knew how to do.