It was the start of the third week of our voyage when the monsignor was killed. He and his party had joined us at Bristol, seeking passage to the New World. It was not unusual for the Church to send expeditions across the great ocean; after all, there were colonists whose spiritual needs had to be attended to, and the pagan aboriginals to be brought into the fold by the holy shepherds. In my innocence I did not question why our vessel had been chosen - that is until the first mate revealed what he knew.

"Ha! No wonder our captain has been minding his tongue since the start of the voyage!"
I looked up from rent in the sail that we were repairing. The first mate gestured towards the monsignor who was standing by the taff rail, gazing across the grey waters.

"What do you mean?" I asked.

The first mate bent once more to his task, and in doing so took the opportunity to answer me in a conspiratorial whisper.

"Did you not see, lad? Our black crows have sharp beaks. They are part of the Congregation for the Doctrine of the Faith, and him there is the master of this particular flock."

I was none the wiser, and I told the first mate so. He shook his head.

"The Inquisition, lad. That's who they are."

I was only a boy of fifteen years at the time, and I was still very much a pious prig. My mother had sent me to sea, my soul protected by as many religious charms as she could drape around my neck. As a consequence of my upbringing, and the captain keeping me somewhat apart from the roughness of the below-decks mess, I was still something of an innocent in the ways of the world. So, I did not understand the first mate's caution, and I told him so: "But they guard our souls and protect us from heresy!"

The first mate laughed, then glanced over his shoulder as if making sure we would not be overheard. "I suppose they do, but at what cost?"

"What does a man gain by profit if he loses his soul?"

The first mate looked strangely at me, then sent me on an errand that took me most of the rest of the watch. By the time I returned, the sail had been mended and the first mate was reluctant to continue our conversation.

After this incident I found that I had been reassigned as mess boy to the monsignor and his party. I was pleased with this, as it took me away from some of the more tedious of my duties; however, the crew made fun of me and my devotions. Some of the more worldly men even went so far as to suggest that they would make sure I would be cured of my religious fever when we next made landfall, but they were careful never to do it in the hearing of the captain or his passengers.

I remember the night the monsignor was killed. The sea was calm and the wind was steady. For some reason I was finding it difficult to sleep, and so I lay in my hammock listening to the noises of the ship as it carried us westwards to the Virgin Territories. My reverie was interrupted by a commotion on deck - raised voices; footsteps; a scuffle. For a minute there was silence, then I heard a voice cry out, "Man overboard!"

Quickly I rolled out of my hammock and scrambled up the ladder and onto the deck. I stood in the moonlight, shivering in the night air as it played around my bare legs, and looked to see what the trouble was. There, by the port-side rail, a figure was standing and pointing out to sea. Again came the cry of distress: "Man overboard!"

I rushed to the rail. As my eyes adjusted to the light, I saw that the lookout was none other than our navigator. He barely glanced at me. "Can you see him, boy?"

I strained my eyes, but I could barely make out the phosphorescent tops of the waves. "Who?"

There were more footsteps from behind, and I was jostled as more of the crew ran to the side of the ship.

"The jumper! Who else?"

I could see no one, but my protests were drowned by the voices of the others. Then the captain's voice rose above them. "Reef the sails! Bring us about! Bos'n - get a crew for the boat! You! Boy! Rouse the others and take a roll! Find out who is missing!" This last order was addressed to me. I ran through the passageways of the ship, banging on the bulkheads and hammering on cabin doors to rouse the inhabitants of the compartments. Curses greeted me, but the captain's authority protected me from the sleepers' wrath. It was only when I came to the monsignor's cabin that my summons was ignored. I hesitated: this was, after all, a cabin that had been given to a most holy man. I knocked on the cabin door one more time, but more forcefully. Again, there was no reply. Gathering my courage and readying my apologies, I lifted the latch and entered the cabin - carefully and with respect for the monsignor's privacy.

The cabin was lit by a single lantern that swung by a chain from a hook in the ceiling. It cast shadows that swept across the furniture as the ship moved. The bunk was still made: no one had slept in it since I had swept out the cabin the previous morning. There was a small table that was bolted to the deck. On this was a small collection of books. My schooling helped me recognise the scripts in some of them: English, Latin and some Greek. Others I did not recognise. I crossed myself in case they were of the Holy Word; then, in a fit of superstition and in deference to the ways of the sea, I warded off any evil with a muttered prayer to Neptune.

I finished off my rounds below-decks, then returned to where the captain and the rest were gathered. Our boat had been dropped and was heading back along our wake, obviously in search of whoever had gone overboard. There was heated debate and speculation amongst the crowd as to what had happened, and the captain was trying to maintain order. I waited quietly until the captain saw fit to address me. "Well, boy?"

"All accounted for, save the monsignor, sir."

The captain was perturbed by this news. "Are you sure?"

"Aye sir. I am."

The captain turned to the priests, who were shivering in the moonlight, dressed only in the clothes they had managed to struggle into when I woke them. "Holy fathers, can you account for your leader?"

The priests conferred amongst themselves, then the eldest one spoke up. "He is not in his cabin?"

I felt the need to speak. "No, father. And there is no sign that his bed has been slept in."

One of the younger priests shot me a venomous glance at this revelation, which he quickly changed to a look of shocked concern when the captain spoke. "If you do not know where the monsignor is, then it is likely that he is the cause of all this trouble."

The eldest priest nodded. "If that is the case, then you must find his body and bring it back for a Christian burial."

"Of course. I shall do my best holy father, but ... ." The captain swept his arms in a gesture that encompassed the vast and dark seascape.

The eldest priest nodded. "I understand, sir. I know that you will do your best under difficult circumstances. We shall wait below for any news." And, with that, the priests shuffled back to their berths.

I was about to ask the captain what I should do when the youngest of the priests, the one who had previously favoured me with an ill look, returned and called out to me, "You! Boy! Come below."

I looked towards the captain, seeking his permission, but he was engaged in an earnest conversation with the navigator. As I would only be an obstacle to the evolutions on-deck, I followed the father down the ladder. I was surprised when he led me away from the priests' quarters to the passageway by the powder vault. There, he paused to ascertain that we would not be overheard. "Boy - you were in the monsignor's room?"

"I was in his cabin, yes father."

The youngest father sighed in annoyance at my correction. "I shall take that as a yes. Now, boy, was there anything on his lectern?"

"His lectern, father?"

The youngest priest's face darkened. "His table! Do not confuse me with your nautical talk. You English are all alike - damned by your pride for the sea. Now, answer me, boy!"

I swallowed and did my best to sound sincere. "Father, there were some books there. I do not know what they were -"

The youngest priest waved his hand to silence me. "Would you recognise them if you were to see them again? Would you know if they had been moved?"

"Yes father, I think I would."

The youngest father set off in an indignant hurry, back to the monsignor's cabin. I followed him with all the haste my tired body could muster. Inside, the cabin was exactly as I had left it. The youngest priest looked impatiently at me. "Well?"

"It is as I remember it, father."

He leaned close to me, so close that his nose almost touched mine, and he stared into my eyes as if daring me to tell him an untruth. "You are sure?"

"Yes, father."

He stood back, then turned to the table and bent over it, staring at the books that had been left there. He turned the pages back and forth, muttering something under his breath. I listened carefully, trying to make out his words, but they were too soft for me to interpret. Then the youngest priest looked up. "Did you look at these?" I could not lie to him. I nodded, and the youngest priest grunted in response. "Did you recognise anything that you saw?"

"No father."

He looked at me, staring at me for what seemed like an age. Then he smiled. "Of course not. You are a devout Christian, are you not?"

"Yes father."

The youngest priest nodded in satisfaction. "Of course, You are but an innocent cast adrift upon the seas of the world. Go. I will have need of you in the morning. Pax vobiscum."

"Et cum spirito tuo." I gave the response automatically, then fled back to my bunk as quickly as I could. The compartment was empty as all the crew were still above, waiting to see what would come of the monsignor having gone overboard. I soon fell into the blackness of sleep, but I found no rest. Instead, my sleep was hanged by dreams of water rushing into my lungs, choking me.

I was woken in the morning by the first mate shaking me. He growled at me as I opened my eyes. "Up! Up now, you lazy creature! The black crows await your ministrations!" I rose and dressed to carry out my duties for the priests. Their spirits had been subdued by the death of the monsignor, and did not engage me with their usual banter. Only the youngest priest seemed to pay any attention to me. Then, when I had finished bringing them their breakfast and clearing the table, I tended to my own needs. As was my habit, I went to take my meal in the navigator's quarters. Normally I would use this as an opportunity to further my learning in the arts of cartography and plotting a course. Today, however, was different.

The navigator was lying in his bunk, his face turned towards the deck above him. He barely acknowledged my presence. It was only when I spoke to him directly that he took any notice of me. "Can you keep a secret, boy?"

I sat down beside him. "That I can, sir."

The navigator rolled over and lifted his mattress. From the cupboard beneath his berth he drew forth an ornately carved wooden box. Some of the symbols on the box resembled those that I had glimpsed in the books in the monsignor's cabin. I hesitated to take the box from the navigator. "What is the matter?" he asked.

I pointed at the box. "Is it blasphemous?"

The navigator laughed bleakly. "No. See for yourself."

He opened the box and took out a thick silver disc that had been cradled in the box's velvet lining. The disc was composed of numerous interlocking rings that had more of the strange symbols inscribed upon them. I could not fathom its purpose. "What is it?" I asked him. "Is it some kind of toy?"

"No. It is a tool - part of a navigator's art. It helps me to plot where the ship is. Without it, we would have been lost many times."

I took the device from his hands and looked at it in wonder. Numerous toothed wheels linked the rings and, as I turned one, the others moved in circles and loops and epicycles. The navigator looked at me imploringly. "Take it and hide it well from the priests. They would destroy it if they found it. Do not tell me where you have hidden it."

I gaped at the navigator's instruction, unsure of what to do. "You said it was not blasphemous."

"I did. It is merely a tool that man has wrought. But it contradicts their teachings, so they hate it."

"But the priests - they only protect true Christians!"

The navigator shook his head. "Precisely. If I survive this voyage, I shall instruct you in the mysteries of this mechanism. If I do not survive, then you will have learnt a valuable lesson. Now, promise me that you will do as I have asked. Swear to me, by the truth you hold holy!" I was so used to obeying the orders of the ship's officers that I found myself vowing to protect the box and its contents. The navigator sank back into his bunk. "Go now, boy. Before the crows come to feast on my still-living corpse."

I left hurriedly and, true to my oath, hid the box and the disc in a compartment only I knew of.
The navigator's concerns were prescient. Within a few days of the monsignor's fall overboard, the priests had arrested the navigator and accused him of a number of crimes, including murder, bearing false witness and being a Jew. A trial was held, and many of the crew were called as witnesses. I was one of those called, and I answered my inquisitor - the youngest priest - as truthfully as I could. The only matter I held back on was when I was asked if the navigator had shown me any blasphemous tomes or strange artefacts. While I was not sure if the device that had been entrusted to me was blasphemous, I knew that I would be judged complicit in his crimes if I spoke of concealing it. And so I perjured myself. The navigator was judged guilty and placed in chains for the rest of the voyage, and, when we arrived in the New World, he was publicly burned at the stake as an example to others.

It took me many years to learn the secrets of the device that had been bequeathed to me. As I discovered, by manipulating the wheels within the disc, it was possible to show the positions of the stars in the heavens and predict where they would be at any time and any place. I also came to understand how this went against the Church's pronouncements that no man could know the mysteries of Heaven, much less divine the Mind of God. And so I became a navigator and a secret heretic, afraid to reveal my knowledge lest I too be burnt in the town square.

Still, there are nights when I look up from my chart table and gaze into the heavens. Above me I can see the crystal spheres that contain the stars and the planets, with the angels passing between them as they sing the eternal glories of God the Father, God the Son and God the Holy Ghost; and I shiver, knowing that I am a sinner before them. But still I wonder, would it not be simpler and more elegant if the universe were like that one depicted on the mechanism, where the sun is at the centre and all the planets in motion around it?