Paul sees it differently. He says that Bill, impressive as he is, has one intellectual flaw: the absence of a living spark. Stein crawls through the library like a spider in an attic, eating up dead books and spinning them into fine thread. What he makes from them is always mechanical and uninspired, driven by a symmetry he can never change.

This way? I ask.

Paul leads me down the corridor. The Rare Books Room stands off in a corner of Firestone, easy to pass without noticing. Inside it, where some of the youngest books are centuries old, the scale of age becomes relative. Upperclassmen in literature seminars are brought here like children on field trips, their pens and pencils confiscated, their dirty fingers monitored. Librarians can be heard scolding tenure-track professors to look without touching. Emeritus faculty come here to feel young again.

It should be closed, Paul says, glancing at his digital watch. Bill must've talked Mrs. Lockhart into keeping it open.

We are in Stein's world now. Mrs. Lockhart, the librarian time forgot, probably darned socks with Gutenberg's wife in her day. She has smooth white skin draped on a wispy frame made for floating through the stacks. Most of the day she can be found muttering in dead languages to the books around her, a taxidermist whispering to her pets. We pass by without making eye contact, signing a clipboard with a pen chained to her desk.

He's in there, she says to Paul, recognizing him. To me she gives only a sniff.

Through a narrow connecting area we arrive before a door I've never opened. Paul approaches, knocks twice, and waits for a sound.

Mrs. Lockhart? comes the reply in a high, shifting voice.

It's me, Paul says.

A lock clicks on the other side, and the door opens slowly. Bill Stein appears before us, a half-foot taller than either Paul or me. The first thing I notice is the gunmetal eyes, how bloodshot they are. The first thing they notice is me.

Tom came with you, he says, scratching at his face. Okay. Good, fine.

Bill speaks in shades of the obvious, some stopgap between his mouth and mind gone missing. The impression is misleading. After a few minutes of the mundane you see flashes of his aptitude.

It was a bad day, he says, guiding us in. A bad week. Not a big deal. I'm fine.

Why couldn't we talk on the phone? Paul asks.

Stein's mouth opens, but he doesn't answer. Now he's scratching at something between his front teeth. He unzips his jacket, then turns back to Paul. Has someone been checking out your books? he asks.

What?

Because someone's been checking out mine.

Bill, it happens.

My William Caxton paper? My Aldus microfilm?

Caxton's a major figure, Paul says.

I've never heard of William Caxton in my life.

The 1877 paper on him? Bill says. It's only at the Forrestal Annex. And Aldus's Letters of Saint Catherine— He turns to me. Not, as generally believed, the first use of italics— Then back to Paul. Microfilm last viewed by someone other than you or me in the seventies. Seventy-one, seventy-two. Someone put a hold on it yesterday. This isn't happening to you?

Paul frowns. Have you talked to Circulation?

Circulation? I talked to Rhoda Carter. They know nothing

Rhoda Carter, head librarian of Firestone. Where the book stops.

I don't know, Paul says, trying not to get Bill more excited. It's probably nothing. I wouldn't worry about it.

I don't. I'm not. But here's the thing. Bill works his way around the far edge of the room, where the space between the wall and the table seems too narrow to pass. He slips through without a sound and pats at the pocket of his old leather jacket. I get these phone calls. Pick up… click. Pick up… click. First at my apartment, now at my office. He shakes his head. Never mind. Down to business. I found something. He glances at Paul nervously. Maybe what you need, maybe not. I don't know. But I think it'll help you finish.

From inside his jacket he pulls out something roughly the size of a brick, wrapped in layers of cloth. Placing it gently on the table, he begins to unwrap it. It's a quirk of Stein's I've noticed before, that his hands twitch until they have a book between them. The same thing happens now: as he unravels the cloth, his movements become more controlled. Inside the swaddling is a worn volume, hardly more than a hundred pages. It smells of something briny.

What collection is it from? I ask, seeing no title on the spine.

No collection, he says. New York. An antiquarian shop. I found it.

Paul is silent. Slowly he extends a hand toward the book. The animal-hide binding is crude and cracked, stitched together with leather twine. The pages are hand-cut. A frontier artifact, maybe. A book kept by a pioneer.

It must be a hundred years old, I say, when Stein doesn't offer any details. A hundred and fifty.

An irritated look crosses Stein's face, as if a dog has just fouled his carpet. Wrong, he says. Wrong. It dawns on me that I'm the dog. Five hundred years.

I focus back on the book.

From Genoa, Bill continues, focusing on Paul. Smell it.

Paul is silent. He pulls an unsharpened pencil from his pocket, turns it backward, and gently opens the cover using the soft nub of the eraser. Bill has bookmarked a page with a silk ribbon.

Careful, Stein says, splaying his hands out above the book. His nails are bitten to the quick. Don't leave marks. I have it on loan. He hesitates. I have to return it when I'm done.

Who had this? Paul asks.

The Argosy Book Store, Bill repeats. In New York. It's what you needed, isn't it? We can finish now.

Paul doesn't seem to notice the pronouns changing in Stein's language.

What is it? I say more assertively.

It's the diary of the portmaster from Genoa, Paul says. His voice is quiet, his eyes circling the script on each page.

I'm stunned. Richard Curry's diary?

Paul nods. Curry was working on an ancient Genoese manuscript thirty years ago, which he claimed would unlock the Hypnerotomachia. Shortly after he told Taft about the book, it was stolen from his apartment. Curry insisted Taft had stolen it. Whatever the truth was, Paul and I had accepted from the beginning that the book was lost to us. We'd gone about our work without it. Now, with Paul pushing to finish his thesis, the diary could be invaluable.

Richard told me there were references to Francesco Colonna in here, Paul says. Francesco was waiting for a ship to come into port. The port-master made daily entries about him and his men. Where they stayed, what they did.

Take it for a day, Bill says, interrupting. He stands up and moves toward the door. Make a copy if you need to. A hand copy. Whatever will help finish the work. But I need it back.

Paul's concentration breaks. You're leaving?

I have to go.

We'll see you at Vincent's lecture?

Lecture? Stein stops. No. I can't.

It's making me nervous, just watching how twitchy he is.

I'll be in my office, he continues, wrapping a red tartan scarf around his neck. Remember, I need it back.

Sure, Paul says, drawing the little bundle closer to him. I'll go through it tonight. I can make notes.

And don't tell Vincent, Stein adds, zipping up his coat. Just between us.

I'll have it back for you tomorrow, Paul tells him. My deadline is midnight.

Tomorrow, then, Stein says, flicking the scarf behind him and slinking off. His exits always seem dramatic, being so abrupt. In a few lanky strides he's crossed the threshold where Mrs. Lockhart presides, and is gone. The ancient librarian places a wilted palm on a frayed copy of Victor Hugo, stroking the neck of an old boyfriend.

Mrs. Lockhart, comes Bill's voice, fading from a place we can't see. Good-bye.

It's really the diary? I ask as soon as he's gone. Just listen, Paul says.