"I have seen a copy in the library in Paris," I said, turning the book over in my hands, "but I have not read it in detail. The rector's sermon whetted my appetite. And the story of Ignatius-that too is among the tales of the early martyrs?"

"Yes, indeed-the ten primitive persecutions under the Romans," he said, tilting his head slightly as if he found my question strange. "All in Book One."

Just then the door opened, and all the candles wavered along the lecterns as the red-haired young man who had been tidying the chapel earlier leaned in and coughed nervously.

"Master Godwyn, sir? Rector Underhill wants to speak with you about a private matter if you have a moment."

Godwyn looked anxiously at me, then back to the boy.

"You would not mind if I step out for a minute, Doctor Bruno? I am sure I may trust you not to steal the books." He laughed self-consciously.

I waved a hand, eager to examine the Foxe.

"Your books will be safe with me, Master Godwyn."

"Might I ask you to wait until I return, then? The library must not be left open and unattended, you see." He looked apprehensive. I assured him that I would guard the place with my life, and with an anxious backward glance, he followed the red-haired boy out.

I settled myself at Godwyn's large desk and opened the volume of Foxe at Book One, but as I did so, I realised that the librarian had left his bunch of keys behind. A thought struck me. Glancing briefly at the closed door, I grabbed the keys and found among them a small iron key of the size to open a padlock. In the back room, I knelt by the locked chest and fitted it to the lock; to my surprise, it sprung open smoothly to reveal a pile of black cloth. As I lifted this out, I saw that it was an academic gown, placed there to conceal the books beneath. I picked up the topmost volume; it was bound in aged calfskin and felt fragile to the touch, its corners frayed, but it was the title page that caused me to draw a sharp breath and check instinctively to make sure I was alone.

It was a copy of the executed Jesuit Edmund Campion's "Ten Reasons," and the printer's mark showed it had come from Rheims. There was no doubt that this tract, Campion's staunch defence of the Catholic faith, was prohibited in England, and certainly in Oxford. Beneath it I found other texts and pamphlets, equally distasteful to the English authorities, by Robert Persons, William Allen, and other Catholic writers out of Europe. I leafed through them for a moment, my pulse quickening, until I was startled by a creaking timber from the library behind me and remembered that Godwyn would soon be returning. I searched quickly to the bottom of the chest but there were no books in Greek; these were forbidden books of a different sort. Replacing them quickly and re-covering them with the gown, I locked the chest in haste and returned the keys, then seated myself quickly at Godwyn's desk in case he should return.

I concentrated my attention on the Foxe, flicking hastily through the pages in search of the story of Ignatius. The task was not difficult; there, on page forty-six, I found what I had anticipated-a gap in the paper the length of two lines of print, cut so neatly as to leave the surrounding text intact. Only the text that had been pushed under my door was missing, the incision as precise as only a bookbinder's knife or similar instrument could make. Or a penknife, I thought suddenly, catching sight of Godwyn's quill and inkwell on the desk in front of me. But that could hardly narrow the search; every scholar in the college must own one of those.

The latch clicked softly and Godwyn reappeared, closing the door behind him and shaking his head to himself.

"I am sorry to abandon you, Doctor Bruno-Rector Underhill wanted to discuss which of poor Roger Mercer's books should be given to the library's collection. Did you find what you wanted?" he asked pleasantly.

"I fear the rats have been at your books, Master Godwyn," I whispered, beckoning him closer and turning to the ravaged page forty-six, which I held open in front of him. He looked from me to the book with incomprehension for a moment, before a flush of outrage spread over his sagging features.

"But whoever would do such a thing?" he exclaimed, then glanced over his shoulder as if someone might have overheard. "How did you know-?"

"I found the missing lines pushed under my door last night."

"But-why?" Godwyn continued to stare at me as if he feared my wits had fled.

"Look at the passage," I whispered.

He raised the book closer to his face and skimmed the page. When he looked up at me again his expression was one of severe shock.

"Ignatius," he whispered. "'I am the wheat of Christ'-I forget the exact words, but that is the missing part, is it not? Something about the teeth of wild beasts."

I nodded. He looked at the book again and exhaled carefully, as if trying to control his response. "Ah. You think this is a reference to Roger's death?"

"I think that is what whoever sent me those lines wants me to conclude, yes."

He closed the book and frowned, so that the lines in his brow formed deep runnels. "Why you, Doctor Bruno, if that does not seem rude?"

I hesitated again, unsure again how much to reveal.

"I was among the first to arrive in the grove yesterday morning after Doctor Mercer was attacked by the dog." I dropped my voice even further until it was barely audible. "On the evidence of what I saw, I suggested that his death may not have been an accident."

Godwyn's eyes widened until his eyebrows threatened to disappear. "But…they said the gate was unlocked…the wild dog strayed in-"

"My hypothesis was not widely taken up by your colleagues. But it seems that someone else wants to strengthen my conviction that his death was by design." I gestured to the book in his hands. Godwyn scrutinised its cover with as much disbelief as if it had spoken aloud, then turned his keen eyes back to me.

"You think someone is trying to imply that Roger was martyred?"

"I don't know," I said. "Someone certainly wants me to notice a similarity in the manner of his death, but why should Doctor Mercer be considered a martyr?"

Godwyn looked at me in silence for a long while as my whispered question hung in the air.

He shook his head sharply. "I cannot think."

"Who would have access to the books in that back room?" I asked.

"Well, all the Fellows have a key to the library, but they are not supposed to take any books on loan without first checking with me and signing the ledger. The students may only use the library when I am present to keep an eye on them, but…well, I am not always as scrupulous as I might be in that regard." He looked guilty for a moment. "If I need to pop out and there are a few students here deep in their work, it seems harsh to lock them out if only for a short while. It's not as if they can easily steal a book, and I would trust them to take care of the library."

"Well, it seems your trust in someone was misplaced," I said.

Godwyn's face clouded, as if he was only now registering the gravity of the assault on library property. "But I was here in the library until about quarter to five yesterday afternoon, when I locked up and left for the disputation, along with the students who were here."

"And you did not leave the library unattended before a quarter to five?"

"Anyone would think you were a magistrate, Doctor Bruno, with all these questions," he said, forcing a smile, but his eyes were guarded. "I may have had to go and use the privy during that time, I really can't remember, but I'm sure I would not have been gone long enough for anyone to achieve this." He banged the cover of the Foxe with his palm. "It has been very carefully done, I do not think it was a rushed job by someone looking over his shoulder all the while."