Set in Stone, Chapter 17.

“I will have her moved,” Darcy said. “I can send for the Bingleys, if you think you and your father would be comforted by their presence.”

Elizabeth shook her head. “I would rather never see Jane again than expose her to this.”

“As you wish.”

“I should like,” she said, “to be alone for a time.”

Darcy hesitated. She could see him weighing whether this was a reasonable request or a request that should not be granted because the person making it could not be trusted alone.

“I will return shortly,” he said at last, and left.

Elizabeth waited until his footsteps had receded down the hall before she moved. She did not look at Kitty again. She went to the small writing-desk by the window and opened the lower drawer. The Rutinum compositum was kept there. Darcy had said she should take it with meals, but that if she felt an episode approaching she should take an additional measure immediately, and that the supply in the morning room was for that purpose. He had also said, on a separate occasion, that rue in excess was dangerous. He had not specified the dosage at which it became dangerous, but he had said the margin was not wide.

She took the bottle from the drawer and set it on the desk. The glass was brown, which she understood was to protect the contents from light. The label was in Darcy’s hand: Rutinum compositum — morgens und abends, mit Essen. She had been taking it twice daily for three weeks. It had not prevented what had just happened to Kitty.

She uncorked the bottle. The smell was bitter and faintly astringent. She had grown accustomed to it at the prescribed dose. It occurred to her that a larger dose would taste worse, and that this was an oddly trivial concern given what she was proposing, and that she was proposing it because the alternative was to wait for Darcy to derive a solution she was not convinced existed. He had not cured Georgiana. He had been trying for some time — she did not know how long, but the casebook had been thick — and Georgiana had ended badly. She did not wish to end badly. She wished to end, which was not quite the same thing but was near enough for present purposes.

The problem was that the episodes were becoming more frequent, that the Rutinum compositum was not preventing them, and that three members of her family were now stone. The solution was to ensure there would be no further episodes. Darcy had not proposed a method for ensuring this. She was proposing one.

She poured a measure into the small glass that sat beside the bottle. Then a second measure. The glass was now half-full. She considered this and added a third measure. The liquid was dark and viscous. She could see particulate matter suspended in it, which she supposed was the plant material insufficiently strained. It looked medicinal, which she found grimly appropriate.

She raised the glass. Her hand was steady. She noted this without satisfaction. It seemed important that if she were going to do this she should do it deliberately. She was solving a problem. The fact that the solution was also herself was regrettable but not, she judged, avoidable.

The door opened.

She did not turn. She heard Darcy’s footsteps cross the room at speed, and then his hand was on her wrist: not pulling, simply a point of contact that communicated interruption more effectively than a word would have. She set the glass down. She still did not turn.

“How much have you taken?” His voice was quiet and very controlled.

“None yet.”

His hand left her wrist. She heard him exhale, a small sound that might have been relief or simply released tension. She turned. He was standing close enough that she had to look up slightly to meet his eyes, which she did for approximately one second before looking away. She no longer trusted direct eye contact. She did not think her eyes would harm him. He had resisted her compulsions before, and she did not think she was angry enough to turn him to stone. But it was a risk she was not willing to take.

“That is three times the therapeutic dose,” Darcy said. He was looking at the glass. “Possibly four, depending on how carefully you poured.”

“Yes.”

“It probably would not have killed you immediately.” His tone was clinical, which she found steadier than sympathy would have been. “It would make you extremely ill. Possibly it would stop your heart, though that is not the primary effect of rue toxicity. More likely it would cause vomiting, convulsions, and eventual liver failure, which would take longer and be considerably less pleasant.”

“But it would stop the episodes.”

“It would stop everything. That is not a solution.”

“It is a solution,” Elizabeth said. “It is simply not one you find acceptable.”

There was a pause. Darcy moved to the window and stood with his back to her, looking out at the garden. She could see his shoulders rise and fall, the careful regulation of breath that suggested he was choosing his words.

“I have another solution,” he said finally. “It requires your cooperation, not your self-destruction.”

Elizabeth said nothing. She found she was very tired, and that the prospect of cooperation was less appealing than the prospect of simply making the problem stop by whatever means were available. She did not say this. She said: “You have been working on this since Georgiana. You did not manage to cure her then.”

“No.” His voice was flat. “I did not have the catalyst. I believe I know what it is now.”

Elizabeth looked at him. His posture was very straight, the stance of a man holding himself together through will rather than circumstance.

“What is it?” she asked.

Darcy turned. He looked at her directly, which he did not often do. His expression was difficult to read: something between exhaustion and resolve.

“Your blood,” he said. “The blood of Medusa. Combined correctly with the Rutinum compositum, I believe it will cure rather than suppress. I cannot do it without you. You must be willing.”

Elizabeth looked at the glass on the desk, then back at Darcy. The rue was still there. The alternative was also there, standing three feet from her and waiting for an answer she was not certain she wished to give.

“I will need to explain the theory,” Darcy said. “It will take some time. Will you come to the study?”

She should say yes. She understood that the only rational response was yes, that Darcy’s solution was both more likely to succeed and less likely to result in liver failure, and that she had been attempting something reckless without fully examining what reckless entailed. She also understood that she was angry: not at Darcy specifically, but at the situation generally, at Kitty in stone by the door, at the rue that did not work, at herself for being the problem that required solving. The anger was not useful. She set it aside.

“Yes,” she said.

Darcy poured the contents of the glass back into the bottle, and offered her his arm. She ignored it. “Lead the way,” she said.