You see, my father said, that night when Rossi gave me the package of papers, I left him smiling at his office door, and as I turned away I was seized by the feeling that I should detain him, or turn back to talk with him a little longer. I knew it was merely the result of our strange conversation, the strangest of my life, and I buried it at once. Two other graduate students in our department came by, deep in conversation, greeting Rossi before he shut his door and walking briskly down the stairs behind me. Their animated talk gave me the sensation that life was going on around us as usual, but I still felt uneasy. My book, ornamented with the dragon, was a burning presence in my briefcase, and now Rossi had added this sealed packet of notes. I wondered if I should look through them later that night, sitting alone at the desk in my tiny apartment. I was exhausted; I felt I couldn't face whatever they held.

I suspected, also, that daylight, morning, would bring a return of confidence and reason. Perhaps I wouldn't even believe Rossi's story by the time I awoke, although I also felt sure it would haunt me whether I actually believed it or not. And how, I asked myself - outside now, passing under Rossi's windows and glancing up involuntarily to where his lamp still shone - how could I not believe my adviser on any point related to his own scholarship? Wouldn't that call into question all the work we had done together? I thought of the first chapters of my dissertation, sitting in piles of neatly edited typescript on my desk at home, and shuddered. If I didn't believe Rossi's story, could we go on working together? Would I have to assume he was mad?

Maybe it was because Rossi was on my mind as I passed under his windows that I became acutely aware of his lamp still shining there. In any case, I was actually stepping into the puddles of light thrown from them onto the street, heading toward my own neighborhood, when they - the pools of light - went out quite literally under my feet. It happened in a fraction of a second, but a thrill of horror washed over me, head to foot. One moment I was lost in thought, stepping into the pool of brightness his light threw on the pavement, and the next moment I was frozen to the spot. I had realized two strange things almost simultaneously. One was that I had never seen this light on the pavement there, between the Gothic classroom buildings, although I'd walked up the street perhaps a thousand times. I had never seen it before because it had never been visible there before. It was visible now because all the streetlights had suddenly gone off. I was alone on the street, my last footstep the only sound lingering there. And except for those broken patches of light from the study where we'd sat talking ten minutes earlier, the street was dark.

My second realization, if it actually came second, swooped over me like a paralysis as I halted. I say swooped because that was how it came over my sight, not into my reason or instinct. At that moment, as I froze in its path, the warm light from my mentor's window went out. Maybe you think this sounds ordinary: office hours finish, and the last professor to leave the building turns off his lamps, darkening a street on which the streetlights have momentarily failed. But the effect was nothing like this. I had no sense of an ordinary desk lamp's being switched out in a window. Instead it was as if something raced over the window behind me, blotting out the source of light. Then the street was utterly dark.

For a moment I stopped breathing. Terrified and clumsy, I turned, saw the darkened windows, all but invisible above the dark street, and on impulse ran toward them. The door through which I'd made my exit was firmly bolted. No other lights showed in the building's facade. At this hour, the door was probably set to lock behind anyone who walked out - surely that was normal. I was standing there, hesitating, on the verge of running around to the other doors, when the streetlights came on again, and I felt suddenly abashed. There was no sign of the two students who'd walked out behind me; they must, I thought, have gone off in a different direction.

But now another group of students was strolling past, laughing; the street was no longer deserted. What if Rossi came out in a minute, as he certainly would after having switched off his light and locked his office door behind him, and found me waiting here? He had said he didn't want to discuss further what we'd been discussing. How could I explain my irrational fears to him, there on the doorstep, when he'd drawn a curtain over the subject - over all morbid subjects, perhaps? Embarrassed, I turned away before he could catch up with me and hurried home. There, I left the envelope in my briefcase, unopened, and slept - although restlessly - through the night.

The next two days were busy, and I didn't let myself look at Rossi's papers; in fact, I put all esoterica resolutely out of my mind. It took me by surprise, therefore, when a colleague from my department stopped me in the library late on the afternoon of the second day. "Have you heard about Rossi?" he demanded, grabbing my arm and wheeling me around as I hurried past.

"Paolo, wait!" Yes, you're guessing correctly - it was Massimo. He was big and loud even as a graduate student, louder than he is now, maybe. I gripped his arm.

"Rossi? What? What about him?"

"He's gone. He's disappeared. The police are searching his office."

I ran all the way to the building, which now looked ordinary, hazy inside with late-afternoon sun and crowded with students leaving their classrooms. On the second floor, in front of Rossi's office, a city policeman was talking with the department chairman and several men I'd never seen before. As I arrived, two men in dark jackets were leaving the professor's study, closing the door firmly behind them and heading toward the stairs and classrooms. I pushed my way through and spoke to the policeman. "Where's Professor Rossi? What's happened to him?"

"Do you know him?" asked the policeman, looking up from his notepad.

"I'm his advisee. I was here two nights ago. Who says he's disappeared?"

The department chairman came forward and shook my hand. "Do you know anything about this? His housekeeper phoned at noon to say he hadn't come home last night or the night before - he didn't ring for dinner or breakfast. She says he's never done that before. He missed a meeting at the department this afternoon without phoning first, which he's never done before, either. A student stopped by to say his office was locked when they'd agreed on an appointment during office hours and that Rossi had never shown up. He missed his lecture today, and finally I had the door opened."

"Was he in there?" I tried not to gasp for breath.

"No."

I pushed blindly away from them toward Rossi's door, but the policeman held me back by one arm. "Not so fast," he said. "You say you were here two nights ago?"

"Yes."

"When did you last see him?"

"About eight-thirty."

"Did you see anyone else around here then?"

I thought. "Yes, just two students in the department - Bertrand and Elias, I think, going out at the same time. They left when I did."

"Good. Check that," the policeman said to one of the men. "Did you notice anything out of the ordinary in Professor Rossi's behavior?"What could I say? Yes, actually - he told me that vampires are real, that Count

Dracula walks among us, that I might have inherited a curse through his own research, and then I saw his light blotted out as if by a giant - "No," I said. "We had a meeting about my dissertation and sat talking until about eight-thirty."

"Did you leave together?"

"No. I left first. He walked me to the door and then went back into his office."

"Did you see anything or anyone suspicious around the building as you left? Hear anything?"

I hesitated again. "No, nothing. Well, there was a brief blackout on the street. The streetlights went off."

"Yes, that's been reported. But you didn't hear anything or see anything out of the usual?"

"No."

"So far you're the last person to see Professor Rossi," the policeman insisted.

"Think hard. When you were with him, did he do or say anything strange? Any talk of depression, suicide, anything like that? Or any talk of going away, going on a trip, say?"

"No, nothing like that," I said honestly. The policeman gave me a hard look.

"I need your name and address." He wrote down everything and turned to the chairman. "You can vouch for this young man?"

"He's certainly who he says he is."

"All right," the policeman told me. "I want you to come in here with me and tell me if you see anything unusual. Especially anything different from two nights ago. Don't touch anything. Frankly, most of these cases turn out to be something predictable, family emergency or a little breakdown - he'll probably be back in a day or two. I've seen it a million times. But with blood on the desk we're not taking any chances."

Blood on the desk? My legs were weakening under me, but I made myself walk in slowly after the policeman. The room looked as it had on dozens of other occasions when I'd seen it in daylight: neat, pleasant, the furniture in precise attitudes of invitation, books and papers in exact stacks on the tables and the desktop. I stepped closer. Across the desk, on Rossi's tan blotting paper, lay a dark reservoir, long since spread and soaked and still. The policeman put a steadying hand on my shoulder. "Not a big enough loss of blood to be a cause of death in itself," he said. "Maybe a bad nosebleed, or some kind of hemorrhage. Did Professor Rossi ever have a nosebleed when you were with him? Did he seem ill that night?"

"No," I said. "I never saw him - bleed - and he never talked about his health to me." I realized suddenly, with appalling clarity, that I'd just spoken of our conversations in past tense, as if they were ended forever. My throat closed with emotion when I thought of Rossi standing cheerfully at the office door, seeing me off. Had he cut himself somehow - on purpose, even? - in a moment of instability, and then hurried out of the room, locking the door behind him? I tried to imagine him raving in a park, perhaps cold and hungry, or boarding a bus to some randomly chosen destination. None of it fit. Rossi was a solid structure, as cool and sane as anyone I'd ever met.

"Look around very carefully." The policeman released my shoulder. He was watching me hard, and I sensed the chairman and the others hovering in the doorway behind us. It dawned on me that until proven otherwise I would be among the suspects if Rossi had been murdered. But Bertrand and Elias would speak up for me, as I could for them. I stared at everything in the room, trying to see through it. It was an exercise in frustration; everything was real, normal, solid, and Rossi was utterly gone from it.

"No," I said finally. "I don't see anything different."

"All right." The policeman turned me toward the windows. "Look up, then."On the white plaster ceiling over the desk, high above us, a dark smear about five inches long drifted sideways, as if pointing toward something outside.

"This appears to be blood, too. Don't worry; it may or may not be Professor Rossi's. That ceiling's too high for a person to reach it easily, even with a step stool. We'll have everything tested. Now think hard. Did Rossi mention a bird getting in that night? Or did you hear any sounds as you left, maybe like something getting in? Was the window open, do you remember?"

"No," I said. "He didn't mention anything like that. And the windows were shut, I'm sure." I couldn't take my eyes off the stain; I felt if I stared hard enough I might read something in its horrible and hieroglyphic shape.

"We've had birds in this building several times," the chairman contributed behind us. "Pigeons. They get in through the skylights once in a while."

"That's a possibility," the policeman said. "Although we haven't found any droppings, it's certainly a possibility."

"Or bats," the chairman said. "What about bats? These old buildings probably have all kinds of things living in them."

"Well, that's another possibility, especially if Rossi tried to hit something with a broom or umbrella and wounded it in the process," suggested a professor in the doorway.

"Did you see anything like a bat in here, ever, or a bird?" the policeman asked me again.

It took me a few seconds to form the simple word and get it past my dry lips.

"No," I said, but I could hardly make sense of his question. My eyes had finally caught the inner end of the dark stain and what it seemed to trail away from. On the top shelf of Rossi's bookcase, in his row of "failures," a book was missing. Where he had replaced his mysterious book two nights before, one narrow black crevice now gaped among the spines.

My colleagues were leading me out again, patting my back and telling me not to worry; I must have looked white as a piece of typing paper. I turned to the policeman, who was shutting and locking the door behind us. "Is there any chance Professor Rossi is already in a hospital somewhere, if he cut himself, or if someone injured him?"

The officer shook his head. "We've got a line to the hospitals, and we've done a first check. No sign of him. Why? Do you think he might have injured himself? I thought you said he didn't seem suicidal or depressed."

"Oh, he didn't." I took a deep breath and felt my feet under me again. The ceiling was too high for him to have smeared his wrist on, anyway - that was a grim consolation.

"Well, folks, we'll be on our way." He turned to the department chairman, and they went off in low-voiced conference. The crowd around the office door was beginning to disperse, and I moved away ahead of them. I needed above all a quiet place to sit down.

My favorite bench in the nave of the old university library was still being warmed by the last sun of a spring afternoon. Around me three or four students read or talked in low voices, and I felt the familiar calm of that scholar's haven soak through my bones. The great hall of the library was pierced by colored windows, some of which looked into its reading rooms and cloisterlike corridors and courtyards, so that I could see people moving around inside or outside, or studying at big oak tables. It was the end of an ordinary day; soon the sun would desert the stone tablets under my feet and plunge the world into twilight - marking a full forty-eight hours since I'd sat talking with my mentor. For now, scholarship and activity prevailed here, pushing back the verges of darkness.

I should tell you that usually when I studied in those days I liked to be completely alone, undisturbed, in monastic silence. I've already described the study carrels I often worked in, on the upper floors of the library stacks, where I had my own niche and where I'd found that weird book that had changed my life and thoughts almost overnight. Two days ago at this time I'd been studying there, busy and unafraid, about to sweep up my books on the Netherlands and hurry toward a pleasant conference with my mentor. I'd thought of nothing but what Heller and Herbert had written the year before on Utrecht's economic history and how I might refute it in an article, perhaps an article filched efficiently from one of my own dissertation chapters.

In fact, if I had imagined any part of the past at all, then, I had been picturing those innocent, slightly grasping Nederlanders debating their guilds' little problems, or standing, arms akimbo, in doorways above the canals, watching some new crate of goods as it was hauled up to the top floor of their houses-cum-warehouses. If I had had any visions of the past, I had seen only their rose-tinted, sea-freshened faces, beetling brows, capable hands, heard the creaking of their fine ships, smelled the spice and tar and sewage of the wharf and rejoiced in the sturdy ingenuity of their buying and bartering.

But history, it seemed, could be something entirely different, a splash of blood whose agony didn't fade overnight, or over centuries. And today my studies were to be of a new sort - novel to me, but not to Rossi and not to many others who had picked their way through the same dark underbrush. I wanted to begin this new kind of research in the cheerful murmur and clang of the main hall, not in the silent stacks, with their occasional wearily treading footsteps on distant stairs. I wanted to open the next phase of my life as a historian there under the unsuspecting eyes of young anthropologists, graying librarians, eighteen-year-olds thinking of their squash games or new white shoes, of smiling undergraduates and harmlessly lunatic professors emeritus - all the traffic of the university evening. I looked once more around the teeming hall, the rapidly withdrawing patches of sunlight, the brisk business of the doors at the main entrance swinging open and shut on bronze hinges. Then I picked up my shabby briefcase, unsnapped the top, and drew out a thickly full dark envelope, labeled in Rossi's handwriting. It said, merely: SAVE FOR NEXT ONE.

Next one? I hadn't looked closely at it two nights before. Had he meant to save the information enclosed for the next time he attempted this project, this dark fortress? Or was I myself the "next one"? Was this a proof of his madness?

Inside the open envelope I saw a pile of papers of different weights and sizes, many dingy and delicate with age, some of them onionskin covered with dense rows of typing. A great deal of material. I would have to spread it out, I decided. I went to the nearest honey-colored table by the card catalog. There were still plenty of people around, all friendly strangers, but I looked superstitiously over one shoulder before drawing out the documents and arranging them on the table.

I had handled some of Sir Thomas More's manuscripts two years before, and some of the elder Albrecht's letters from Amsterdam, and more recently had helped to catalog a set of Flemish account books from the 1680s. I knew, as a historian, that the order of any archival find is an important part of its lesson. Digging out a pencil and paper, I made a list of the order of the items as I withdrew them. The first, the topmost, of Rossi's documents proved to be the onionskin sheets. They had been covered by the neatest possible typing, more or less in the form of letters. I kept them carefully together without letting myself look closely.

The second item was a map, hand drawn with awkward neatness. This was already fading, and the marks and place-names showed up poorly on a thick foreign-feeling notebook paper obviously torn from some old tablet. Two similar maps followed it. After these came three pages of scattered handwritten notes, in ink and quite legible at first glance. I set these together, too. Next was a printed brochure inviting tourists to "Romantic Roumania," in English, that looked from its Deco embellishments like a product of the 1920s or '30s. Next, two receipts for a hotel and for meals taken there. Istanbul, in fact. Then a large old road map of the Balkans, untidily printed in two colors. The last item was a little ivory envelope, sealed and unlabeled. I set it aside, heroically, without touching the flap.

That was it. I turned the big brown envelope upside down, even shook it, so that not so much as a dead fly could go unnoticed. While I was doing this I suddenly (and for the first time) had a sensation that would accompany me through all the ensuing efforts required of me: I felt Rossi's presence, his pride in my thoroughness, something like his spirit living and speaking to me through the careful methods he himself had taught me. I knew he worked swiftly, as a researcher, but also that he abused nothing and neglected nothing  - not a single document, not an archive, however far from home it was located, and certainly not an idea, however unfashionable it might be among his colleagues. His disappearance, and - I thought wildly - his very need of me, had suddenly made us almost equals. I had the sense, also, that he had been promising me this outcome, this equality, all along, and waiting for the time when I would earn it.

I now had every dry-smelling item spread on the table in front of me. I began with the letters, those long dense epistles typed on onionskin with few mistakes and few corrections. There was one copy of each, and they seemed to be in chronological order already. Each was carefully dated, all from December 1930, more than twenty years before. Each was headed TRINITY COLLEGE, OXFORD, without any further address. I glanced through the first letter. It told the story of his discovery of the mysterious book, and of his initial research at Oxford. The letter was signed, "Yours in grief, Bartholomew Rossi." And it began - I held the onionskin carefully even when my hand started to shake a little - it began affectionately: "My dear and unfortunate successor - "

My father suddenly stopped, and the trembling of his voice made me turn tactfully away before he could force himself to say anything more. By unspoken consent, we gathered our jackets and strolled across the famous little piazza, pretending the facade of the church still held some interest for us.