One such conversation set me on the path that brought me here.

I was drinking mead on a chilly spring evening with two friends and two strangers. Strangers were common enough near Reykjavík; someone was always sailing in from somewhere. These particular two were big, hulking men, even larger than me, blond and blue-eyed and fresh from raiding and pillaging the coast of Ireland. All of us had been raiders at some point, and to many people we were the scariest things in the world. Naturally, we were scared of something else, and that night we were trying to frighten one another. I mined the stories told on dragon ships, mutterings in the dark that hardened, seasoned men found terrifying. Some were about men who turned into wolves on the full moon. Others were about degenerate creatures that ate the flesh of the dead and took on the form of the one they last consumed. And some that I had heard, more than once, concerned beings who drank blood and lived for centuries. They had inhuman strength and speed and could tear a berserker apart in seconds without shield or sword. But, more than this, they possessed a cold intelligence. They were the power behind the Romans, the tales said. They were slowly moving north and would eventually come to Viking lands; judging by a few mysterious deaths, a powerful one had supposedly established itself in Prague, the capital of Bohemia. The term today is vampire, but that is a modern word applied in the last few centuries. There were different names used back then: revenant or diable, in French; blutsauger in Germany; in Bohemia we were chodící mrtvola, a walking corpse. Every so often, the legends said, these creatures made others like them, damning men’s souls forever with evil so foul that they could not stand the kiss of sunlight on their skin.

“Would it not be grand to be immortal?” I said to the men crowded around a wooden table. “Think of what treasure could be hoarded. What influence one could wield. Think of the lands one could visit if only there were time enough to do it.”

“You would do this if you could?” one of the strangers said. He carried a large hammer instead of a sword, and I remember thinking at the time that it suited him. “If these creatures truly exist, you would sacrifice your humanity?”

“Well, not now, of course. There is my family to think about. In a younger, more reckless time of life, however, I would leap at the chance.”

“Truly? You would give up Valhalla, the food and drink of Odin’s table, for what? A sunless, bloodsucking existence on Midgard?”

“You are leaving out the part where I would be incredibly strong and live for centuries.” My companions thought this rejoinder was particularly witty and laughed. Everything was funny when you had drunk enough mead.

“Fine.” The stranger spread his hands. “I grant you your own definition. But you would prefer this to the glory and honor of becoming one of the Einherjar?”

“Again, I cannot say yes now. I have responsibilities to my family and my community. But if I were just starting out again, nothing holding me back, then why not?”

The stranger sat back in his chair and glared at me. “Why not, indeed?” He looked at his companion, who had lost one of his hands in battle. There was an unspoken query on the first stranger’s face, and the one-handed man answered it with an indifferent shrug.

One of my friends tried to change the topic to dragons, but the first stranger interrupted him. “Very well, it is decided. You are Leif Helgarson, are you not?”

I blinked in mild surprise. I could not recall introducing myself or either of my friends introducing me. We had merely begun talking with these strangers in the way veteran warriors will, ready to share laughs but not names unless we planned on seeing them again.

“Yes. Who are you?”

“I am Thor, god of thunder.”

My companions and I thought it was a fine joke and laughed in his face. He did not smile, however, nor did his one-handed companion.

“You say you would become one of these creatures if you had nothing to hold you back,” he said. “My gift to you is freedom to pursue this dream of yours. You are free of your familial obligations, Leif Helgarson. Now you can follow through on your boast and become a bloodsucking immortal. I dare you.”

“What are you talking about?” I said.

One of my friends chimed in. “I want whatever that guy’s drinking.”

“Your family is dead,” the stranger insisted. “Nothing is holding you back.”

All laughter ceased. “That is not funny.”

“I do not jest,” the stranger replied.

“My family is well. I saw them this morning.”

“Lightning can strike at any time, and it struck a few moments ago.”

I wanted to crunch my fist into his face, but if I wished to join the Althing my fighting days were over. I would profit nothing from starting a brawl. So I roughly excused myself instead and left the tavern, a bit unsteady on my feet, and discovered that a storm had rolled in while I’d been drinking. I had some trouble mounting my horse but eventually succeeded. I hurried home in the rain, telling myself that I was being silly, that could not have been Thor, it was just a big bastard with a hammer.

My dread mounted in equal measure with my denial as I rode. That was never Thor. But what if it was? What if a careless moment of drunken braggadocio had doomed my family?

You may imagine the desolation I felt when I burst through my door and found my wife and sons strewn limply about the lodge, their lives burned away. My heart became ash and I tasted nothing but bile.

Guilt and grief: My throat closed with it, choking me and letting nothing but animal cries escape. I sank to the floor, weeping for them and telling them, when I could manage, that I was so very sorry.

Sometimes I cheer myself by thinking perhaps they went to Freyja’s hall, Fólkvangr, for they did nothing wrong. But that would have been a mercy of the gods, and Thor was anything but merciful. More likely they went to Hel, a sunless, cheerless realm, because I, in a fit of inebriated bombast, laid claim to powers beyond my ken.

I built them a funeral ship and sent them to sea aflame. No land has been green for me since that day. It is all a waste, all emptiness. Inside me an emptiness grew as well, a black gnawing void that threatened to eat me and give Thor his victory. But I fought against this: I filled that emptiness with rage and discovered that my rage was as boundless as the emptiness. And so I did not break. I had my purpose: become an immortal and kill Thor. He had dared me.

And, in truth, it was the only way I could see to even challenge him. What cared I for damnation? I was already damned. But immortality, strength, speed—these I would need if I were to ever avenge my family, and I vowed to do so at any cost.

I left my farm, traveled to Reykjavík, and hired myself on the next boat to Europe. By a bit of mercenary work here and a bit of banditry there, I made my way back to the North Sea and thence up the Elbe to Hamburg. This was in 1006, well before the Polish King Mieszko II burned Hamburg to cinders. With some inquiry and patience, I found work as a sword arm to a merchant who wished to trade upriver with Prague. He was anxious to establish ties with the court of Duke Jaromír, part of the Přemyslid dynasty in Bohemia. He taught me some of the language during the trip, but it was practically useless. He did not know Old Norse, and my German was terrible at the time, but I kept at it because I knew I would need to ask questions of the locals if I were to find this blood-drinking immortal who had supposedly settled in Bohemia.

We turned up the Vltava River to get to Prague. It was not then the beautiful city it is today. Like all other medieval cities, Prague was dirty and mean and full of the illiterate and diseased. I myself fit that description fairly well. There was a thriving slave market in the city, which was a trade center for the region, with many merchants basing their operations there.

Once I’d helped to unload the German merchant’s cargo, I got a job at the docks guarding warehouses; it was boring work, but it kept my belly full and paid for a room while I learned the language. Eventually, when snow began to fall, I started to frequent the taverns and ask questions. Sometimes my questions were met with drunken amusement and were openly mocked. To these places I never returned. In other places, my questions were met with stony silence or a curt warning that such things were not spoken of there. I was kicked out of one establishment for daring to ask. I noticed that these places were all located near the old Přemyslid fortress on the west side of the river—it’s the Hradcany Castle now, but English speakers simply call it Prague Castle.

For two months I made a nuisance of myself. I had met every drunk in the town and many occasional drinkers besides and learned nothing of significance. I was about to give up and try elsewhere—Rome, I heard, was the place to go—when a small man, richly dressed with a high collar underneath a gray squirrel cloak, sat down next to me in a tavern on the west side. His dark beard was trimmed into a thin line around his jaw, but his mustache was thick and groomed. He spoke the Bohemian language, but he had a foreign accent that I could not place. The barkeep served him quickly and nervously and scampered away. He did not want to overhear our conversation.

“You are the northman who has been asking questions about blood drinkers,” he said. It was not a question; it was identification.

“Who are you?” I asked.

“I am no one of importance. I represent a gentleman—a scholar—who may be able to answer your questions. Would you like to meet him?”

I peered at him suspiciously. “Is this an invitation to my death? I have seen people frown at me and heard the muttered oaths. The Christians, especially, do not like me speaking of this. Are you one of them? You have a group of men outside ready to silence me forever?”

“Hardly,” the small man snorted. “This gentleman merely wishes conversation. I think you might survive.”

“Why does he not come here and talk to me? Tell him where I am.”

“He already knows where you are. That is why I am here. You must forgive him; he is somewhat of a recluse. He is obsessed with converting his scrolls to books. Have you heard of these?”

“Yes, I have seen books. The Christian monks and priests have them.”

“Precisely. But they have only one book, do they not? My employer has many in his library and is making more. He has learned how to make paper from the Arabs, who learned it from the Chinese. Now he employs the literate in copying his scrolls and turning them into books.”

“Why not simply copy the scrolls?”

“Books are sturdier. Easier to travel with. Are you able to read?”

I shrugged. “I know the word tavern in three languages. That probably does not count.”

The small man chuckled. “No, but that is a good word to know. Perhaps there is much you can learn from my employer. Will you not return with me to his study?”

“This is not an ambush?” I asked again.

He finished his drink and toyed with his mustache before answering. “I will not raise a hand against you. Neither will anyone I’ve employed, nor anyone my employer has hired. Good enough?”

“What about your employer?”

“I cannot speak for him. He is a … violent defender of knowledge, shall we say. But I believe he merely wishes to speak with you. That is all I can say.”

“Hmm. What is your employer’s name?”

“He will give it to you if he wishes.”

“Very well. I will go with you.” We settled our tabs with the barkeep and walked into a softly moonlit evening in the Little Quarter. The small man did not offer light conversation but kept silent. I kept my eyes moving and a hand on my sword hilt. After three blocks we stopped at the gate of a walled compound. The guards there recognized the small man.

“I have brought him,” he said, and the gates were opened. Beyond them was an impressive house—impressive for the time, anyway—its façade lit by torches in the brick courtyard in which we currently walked. There was a fountain. Flower beds. Architecture. This bookbinder was a wealthy man.

My guide led me into a candlelit foyer. The floors were marble and covered with Persian rugs. Tapestries hung on the walls. It was the sort of wealth one saw only when raiding a monastery, and it exceeded anything in my personal experience. I caught but a few glimpses of the rooms on that floor, because the mustachioed man led me down a flight of stairs into the basement. There was a hallway with periodic candle sconces and several doors that I could see. We stopped at the first one and my guide knocked.

“Come,” a voice said from the other side.

We entered a room lined entirely with bookshelves. Of course it was a library, but I had never seen such a room before. A long worktable scattered with loose pages, scraps of leather, and strange tools led my eyes to a pale man standing at the end of it. Though it was winter and quite chilly in the basement—and I was grateful for the warmth provided by my cloak—this man seemed unaffected by the cold. He wore rich purple silk imported from Asia; the fabric was new to me, but I recognized immediately that it was far superior to linen and wool. He was examining a book he’d apparently just pulled from a wooden vise.

“Ah, you must be the northman. Magnificent,” he said.

“You must be the mysterious scholar,” I replied. “I am Leif Helgarson.”

“It is my pleasure to meet you.” He placed his book gently on the table and inspected me frankly. “Tall, blond, and Viking. Excellent.”

I could have noted at that point that he was none of these, but I had no wish to be rude. Yet. “And what shall I call you?” I asked.

He paused to consider, communicating that any name he gave me would not be his true one. “You may call me Björn.”