“Do you believe the girl is guilty?”

What a question. One which I had asked myself on many occasions during my journey.

“I do not know. That is a matter for law, not reason.”

He smiled at this, as though I had made some cutting remark. Lower told me later that he had been for many years a lawyer, before the rebellion had swept him into office.

“In reason, then. Tell me what you think.”

“The hypothesis is that Sarah Blundy killed Dr. Grove. What evidence is there? There is a motive, in that he discharged her from his employ, although many servants are discharged and fortunately few take such revenge. She acquired arsenic on the day she was discharged. She was in New College on the evening of Dr. Grove’s death and was reluctant to own it. Certainly, the evidence supports the hypothesis proposed.”

“Your method has a weakness, though. You do not mention all the evidence. Only that which supports the hypothesis. As I understand it, other facts support an alternative, which is that you could have killed him, as you were the last person to see him alive, and also had access to the poison had you wanted to kill him.”

“I could have, but I know I did not, and I had no reason to do so. Any more than Dr. Wallis had, or Lower or Boyle.”

He accepted this point—although why I was telling him I did not know—and nodded. “So it is the combination of different qualities of facts which you believe important. And you conclude that she is indeed guilty.”

“No,” I replied. “I am very reluctant to do so.”

Thurloe affected to look surprised. “But surely that goes against the scientific method? You must accept it, until you have an alternative hypothesis.”

“I accept it as a possibility, but would be reluctant to act on it unless it was more secure.”

He stood up slowly, in the way the old are forced to do by the stiffness of their joints. “Please help yourself to a glass of wine, doctor. I will return to discuss this matter further in a short while.”

I revised my estimate of him as I poured myself a glass. An order is an order, however mildly it is given—Thurloe, I decided, was gentle because he had never needed to be other. It never occurred to me to say that Lower was expecting me, that I was hungry, or that I saw no reason to kick my heels waiting on his pleasure. I stayed where I was, for half an hour or more, until he returned.

With him, when he finally came back, was Jack Prestcott, his jail cell and shackles now a mere memory, grinning with embarrassment as he followed Thurloe into the room.

“Ah,” he said brightly, as I stared at him in outright astonishment, for he was the very last person I ever expected to see again, let alone in such circumstances. “The Italian anatomist. How do, good doctor?”

Thurloe smiled sadly at both of us, then bowed. “I will leave you both to a discussion,” he said. “Please do not hesitate to call me if required.”

And he left the room, leaving me to gape idiotically. Prest-cott, a burlier man than I remembered and certainly more cheerful than he had been on our last meeting, rubbed his hands, poured himself a glass of ale from a jug on the sideboard and sat down in front of me, scrutinizing my face to see if there were any danger signals.

“You are surprised to see me. Good. I’m glad to hear it. You must admit, this is a pretty good hiding place, don’t you think? Who’d think of looking for me here, eh?”

He certainly seemed to be in good spirits, very much like someone who had not a care in the world, rather than a man faced with the prospect of imminent hanging. And what, I wondered, was he doing in the house of a man like Thurloe?

“Simple enough,” he said. “My father and he were acquainted, after a fashion. I threw myself on his mercy. We outcasts must stick together, you know.”

“So what do you want? You are taking a risk announcing your presence to me, are you not?”

“We shall see. Thurloe told me what you said, but would you mind going through the matter again?”

“Which matter?”

“About Dr. Grove. He was good to me, and the only person in Oxford I had an affection for. I was sorely grieved when I heard what had happened.”

“Considering how ill you would have used him had he visited you the evening of your escape, I find that difficult to credit.”

“Oh, that,” he said contemptuously. “I didn’t hurt Wallis by tying him up, and I wouldn’t have hurt old Grove. But what is a man to do? Die on the scaffold to avoid being uncivil? I had to escape and this was my only opportunity. What would you have done?”

“I would not have attacked someone to start with,” I replied.

He brushed the point aside. “Now think a minute. Thurloe tells me that the magistrate hovered ominously around you for a moment. What if he had clapped you in irons—as he might have done, you know, for a papist would be a popular choice. What would you do? Sit tight and hope the jury was sensible? Or decide they are likely to be a bunch of drunken good-for-nothings who would hang you for the pleasure of it? I may be a fugitive, but at least I am alive. Except that Grove’s death concerns me, and I would help if it were possible, for he was kind to me once and I revere his memory. So tell me, what has been going on?”

Again I went through the story. Prestcott proved a more appreciative audience, twisting about in his chair, getting up to refill his glass, punctuating my remarks with loud exclamations of approval or dissent. Eventually, I concluded my tale for the second time.

“And now, Mr. Prestcott,” I said sternly, “you must tell me what this is about.”

“What it is about,” he said, “is that I now understand a good deal more than I did a few moments ago. The question is, what am I to do about it?”

“I cannot advise you until I know what you mean.”

Prestcott took a deep sigh, then looked me straight in the eye. “You know the Blundy girl was his strumpet?”

I said I had heard the story, but added that the girl did not admit it.

“Of course not. But it’s true. I know because we went together briefly last year before I knew what she was. Then she moved onto Grove, and seduced him, poor old man, into her clutches. It was simply done; he had an eye for prettiness, and she can be very compliant when she puts her mind to it. She was furious when he dismissed her. I came across her just afterward, and believe me, I have never seen such a terrifying countenance in my life. She looked like a devil, and was snarling and spitting like an animal. He would pay for it, she said. And pay dearly.”

“Meaning?”

He shrugged. “I thought it just womanly excess at the time. Anyway, shortly after I had my regrettable experience and ended up in jail, so I lost contact with the outside world. Until I escaped. When I walked out of the castle, I had not a clue what to do next. I had no money, no proper clothes, nothing. And I thought I’d better hide lest the alarm was raised. So I went to the Blundys’ cottage. I had been there before, and knew it.”

He had slipped quietly up the muddy alleyway to Sarah’s door, and peered through the window. It was quite dark inside, and he assumed that no one was there. He rummaged around to see if there was any food he could take, and was eating a crust of bread when Sarah returned.

“She had an exhilaration which frightened me,” he confessed. “She was surprised to see me, of course, but when I told her I wouldn’t hurt her and didn’t intend to stay long, she relaxed. She had a small bag with her and, as I thought it might have some more food in it, I took it from her.”

“She let you have it?”

“Not exactly. I had to force it from her.”

“And I take it there was no food there?”

“No. There was money. And a ring. Grove’s signet ring,” he said, then paused to rummage in his pocket. He took out a small packet of crumpled paper, which he unwrapped carefully. Inside was a ring with a carved blue stone in the center.