"No," I agreed. "And no one could have come in while you were at the disputation?"

"Well, as I say, the Fellows all have keys, but they were at the disputation too," he said, but his eyes swerved away from mine as he said it.

All except James Coverdale, I thought, but I had already dismissed him as the person most eager to persuade me away from the theory of murder.

"No one else at all has a key?"

"Only the rector. Oh-and, of course…" Here he hesitated and his demeanour became awkward.

"Who?" I pressed.

"Mistress Sophia has the use of her father's key sometimes," he said, cupping a fist against his mouth as if he were about to cough. "She has a fancy that she can be as good a scholar as any and he indulges her in it. I suspect it comes of the loss of his son-though, of course, that is his business." He shook his head. "Mind you, I would not allow any daughter of mine such freedom, if I had one, for women's minds are not made for learning and I confess I fear for her health-but I must be thankful that he only permits her to visit at times when the scholars are unlikely to be present. Otherwise she has them all panting after her like dogs in season, Doctor Bruno, and I don't want my library used for that sort of thing-at least with her own key, she can come in when the young men are out at public lectures."

"Does she use the library when you are not here to supervise?"

"Oh, I expect so," Godwyn said, as if the matter were out of his hands. "If she has her father's permission I can hardly gainsay him-besides, she is not going to steal the books, is she?"

No, I thought, but might she have used her key to gain access last night, knowing the whole college would be at the Divinity School for over an hour? She had not betrayed a flicker of recognition when I mentioned the quotation last night, but that was not in itself proof of ignorance. But why on earth would Sophia write to me anonymously and then feign ignorance when she had a chance to discuss the matter with me alone? The person who had written to me was clearly anxious not to be identified as the source of the information, scant as it was. Could it be that Sophia knew something about someone in the college, but could not be seen overtly to denounce him? Could that someone be her own father?

"Thank you, Master Godwyn," I said, rising from his chair to take my leave.

"Oh, but I have not yet shown you our illustrated manuscript of Saint Cyprian's letters which Dean Flemyng also brought out of Florence," he began, his eyes lit with disappointment. I studied his face as I apologised for leaving, reflecting that those large, melancholy eyes lent him an air of disarming frankness. But I now knew that Godwyn was also a man hiding his own secrets, and I reminded myself that I must not trust the face that any of them presented to me or to the world. As William Bernard had so pointedly told me that first night, no man in Oxford was what he seemed.

Trying to marshall my thoughts, I emerged into the quadrangle, now lit by the first tentative glimmers of sun I had seen since leaving London. Streaks of cloud still lingered overhead, but the determined rain of the past three days seemed temporarily to have abated. The clock above the archway to the chapel and library staircase showed it to be just gone half past eight; the college felt ominously quiet.

I paused to look up at the windows of the rector's lodgings, wondering which room might be Sophia's and how I might find a way to see her again today, despite her father's explicit ban, when I remembered with a sudden curse that I had half promised to go hunting with Sidney and the palatine Laski at Shotover Forest. I decided that I would walk over to Christ Church and excuse myself to Sidney in person. Sidney would be angry, I knew, and I had every sympathy for him, being saddled with the Pole from dawn till night, but I could hardly be considered an asset to any hunting party even when my attention was not so distracted by trying to catch a killer; I had no talent for gentlemen's sports and no opportunity to learn them in my youth, as he had. Sidney could make the necessary enquiries about hunting dogs while he was there; I reasoned I could make more useful progress by staying in the town. The two people whose confidence I most wanted to gain were Thomas Allen and Doctor William Bernard; both, I suspected, would have at least some knowledge of the underground Catholic network, which in turn may have a connection with Mercer's death, though I knew very well that if they had any such contacts they would not admit them to me easily.

Reluctantly I returned to my own chamber, where I washed thoroughly in cold water, since the scholars of Oxford seemed to possess nothing so civilised as a bathhouse, reflecting that I must ask Cobbett about seeing the college barber to have my beard trimmed and the laundress to wash my shirts, as it appeared we were destined to stay at least three more days. My stomach rumbled loudly as I dressed; hunger had crept up on me while I was at my ablutions, and I took Walsingham's purse from my travelling bag and hung it at my belt, deciding that I would venture into the town to see if I could find any place that would sell me something to eat at this hour on a Sunday.

The courtyard was still empty when I stepped out from my staircase, and seemed unnaturally quiet; the students apparently kept to themselves on Sundays. I was about to cross to the gatehouse when Gabriel Norris emerged from his staircase in the west range carrying a leather bag slung over one shoulder. Instinctively I took a step back into the shadows, wishing to avoid further speculation with him about what may or may not be said at the inquest. He was dressed all in black, but it was clear even from a distance that his doublet and breeches were satin and expensively cut, and he wore a short cloak around his shoulders that gleamed with the sheen of velvet. He glanced briefly around the courtyard but appeared not to notice me, still half hidden, before setting off with a quick tread toward the gate. Something about his haste struck me as curious. I recalled that he had turned down his invitation to hunt with Sidney today, and wondered what prior commitment could be more attractive to a young man than that? I decided then that it might be amusing to follow him, since I had planned to go into the town anyway; after his own confession about his nocturnal expeditions, and Lawrence Weston's report of the rumours about his preferences, I half hoped I might catch him out in some illicit tryst and prove Weston's theory true. Then, if the right moment arose, I could make use of any such proof to dissuade Sophia away from him for good-if, indeed, he was the indifferent object of her affections.

I allowed him a few moments to gain some distance so that he would not notice me trailing behind. Waving to Cobbett through his small window, I leaned tentatively out of the main gate into St. Mildred's Lane to see Norris already some way ahead, walking at a brisk pace north in the direction of Jesus College. I had to half skip to keep up with his long strides, staying close to the wall of Exeter College as we passed it, but not so much that I would seem to be doing anything other than taking a casual stroll if he happened to turn around and spot me.

The lane was clogged with mud after the past days' rain, and Norris fastidiously sidestepped the worst of the ruts and puddles, stopping at one point to wipe a splatter of dirt from his fine leather boots with a gesture of irritation. Where St. Mildred's Lane met Sommer Lane he turned right without hesitation, and after a moment's pause I followed, keeping in the shadow of the old city wall which rose up solidly on my left like a fortress. There were few souls abroad in the street, only one or two couples in their best clothes, no doubt heading for one of the city's many parish churches. Bells pealed from somewhere up ahead, announcing a service.