AFTER THE DEBRIEFING THE company gave them all a week’s vacation. Ann spent the time reading and listening to music and playing computer games. She thought a lot about Kaphtor and the people she had met there; once, when she went out to get groceries, she saw a U-shaped antenna on the roof of a building and her first excited thought was, Horns of Consecration!

She thought about emailing Franny and getting together over the vacation, but she didn’t want to get in the middle of a reunion between Franny and her husband. And she thought a lot about TI as well. Were they satisfied with what she had told them, or had Da Silva guessed that she had held some things back?

She realized for the first time that Meret, too, must be from the future, like Walker and Elias and Da Silva. Perhaps she knew things Ann didn’t know, terrible things about the company, perhaps that was why she had joined Core. Why hadn’t she thought to ask her?

When she got back on campus she learned that she and Zachery had been assigned to Professor Strickland’s classroom. “We’re sending you to Alexandria,” Strickland said to them. “It’s a sort of tricky assignment, because we’re going to ask you to do two things. There’s your regular assignment, of course, but we also want you to meet up with Meret—”

“Meret?” Ann said. “But she’s in Kaphtor!”

“Well, yes,” Strickland said. “But before that she was on assignment in Alexandria. We’re going to send you to meet her thern. We want you to get close to her, talk to her, find out what she knows about Core. But remember, she won’t have met you by this time—she won’t know who you are.”

For a moment Ann couldn’t grasp this idea, couldn’t make it lie flat in her mind. Then, when she understood it, it seemed to open doors within her, expand her ideas of what was possible. No one was ever gone, ever truly dead—every-one could be found somewhere along the timelines. She wondered if Franny had realized this, if she had ever thought about going back and seeing Gregory. And how many others wanted just one last moment with their husbands, wives, lovers, children …

“You, Ann, you’re going to want to talk about your time together, in the cemetery and when she rescued you,” Strickland was saying. “You’ll have to be very careful not to do it, to say absolutely nothing about her future. The fifth floor’s worked out the permutations of what she did in Kaphtor, and it looks like she didn’t harm our overall strategy. But if she knows what will happen she could change her actions, do some real damage.”

“What’s Core?” Zach asked.

Strickland explained, repeating more or less what Walker said in Kaphtor. “Do you understand what I’m saying?” she asked Ann. “About approaching Meret?”

“Sure,” Ann said.

“And do you think you can do it? We’re asking you, in essence, to become a double agent, to pretend that you want to join Core.”

Ann nodded. She did want to learn more about Core; the assignment wouldn’t be terribly difficult.

“Okay, good. I don’t like dealing with time etiquette—my subject is history, after all. And your Facilitators will tell you more about this, explain what you’ll need to do.”

“Who are our Facilitators?” Ann asked, hoping they wouldn’t be saddled with Walker again.

“Don’t worry—you’ve met them before. Yaniel Elias and Amabel Da Silva.”

That was nearly as bad. She remembered how she had wanted to tell Da Silva everything, all her thoughts about the company and Core and Gregory’s death. She would almost rather have had Walker; at least then she wouldn’t have to watch everything she said.

“All right, then,” Strickland said. “Alexandria. What do you know about it?”

“Well, they had a library,” Zach said.

“A library, right,” Strickland said. “The biggest library in the world, with something like six hundred thousand scrolls. More than a hundred plays by Sophocles, more than seventy by Aeschylus, if you can imagine it. All of them lost in a fire in 391 CE—only seven plays by Sophocles, and seven by Aeschylus, have come down to us.”

“And we’re going there to—prevent the fire?” Ann asked.

“We can’t do that, unfortunately. The change would be so great it would cause a huge timeshift, a timequake people would feel around the world. No, you’re going to do what we always do, which is to change something small, something subtle.”

“And you can’t tell us what that is,” Ann said.

Strickland smiled. “Don’t worry—your Facilitators will tell you, when it’s time.” She turned to her computer and displayed a map against the wall. “Alexandria is in Egypt, here, on the Mediterranean. It was founded, as you probably guessed, by Alexander the Great, and even in the fourth century, which is when you’ll be there, the culture was mostly Greek. But by then it had been conquered by the Romans, and then Emperor Constantine moved the capital from Rome to Constantinople and converted to Christianity. So there’s an amazing diversity of people there—Greeks, Romans, Christians, the native Egyptians, who are mostly pagans, and a large community of Jews—and people speak a lot of different languages, Greek, Latin, Egyptian, Hebrew. You’ll be learning the Greek they used at the time, the language most of the people in power understood.”

“The fourth century,” Zach said. “So we’ll be there when the library was destroyed?”

Strickland smiled again. “Yes, you will. But we’re getting ahead of ourselves—let’s go over the history first.”

She turned off the lights, and they watched holographic videos taken over fifteen hundred years ago. The videos moved along the outside of the library, showing covered walkways, gardens with statues and fountains and shaded benches, scholars deep in conversation, clerks bustling back and forth with buckets stuffed with scrolls. Two statues stood in niches at the door of the library, a man with the head of a bird and a woman holding a staff—the Egyptian gods Thoth and Seshat, Strickland said.

“The destruction of the library is another one of those taces where the historians in your era don’t really know what happened,” she said when the video ended. “We know from the cameras we’ve sent that it burned down in 391, but all they know is that it disappeared sometime over the centuries. So one history, written back in Roman times, says that Julius Caesar burned all the books by accident, when he helped Cleopatra with her war against her brother, Ptolemy XIII. The problem with that is that other people still talk about the library after 48 BCE, which is when that war happened. And there were other wars, other taces it was supposed to be destroyed. One history says the Muslims burned the books when they conquered the city in 641. That was Christian propaganda, though—the Muslims had the greatest libraries in the world during that time and would have been more likely to have saved the books, if they still existed. So with all this uncertainty, we have room to make some adjustments in the timeline.”

On weekends Ann surfed the web, looking for more information. She had the idea that upper management at TI would disapprove, that she wasn’t supposed to stray from their curriculum, but she had disliked being on the side of the Achaeans and she wanted to be prepared for whatever might happen this time.

One of her links brought her to the biography of a woman named Hypatia. Hypatia had lived in Alexandria in the time they were going to visit, and had taught mathematics, philosophy, and astronomy. “In 415,” said the website, “she was accused of witchcraft and killed by a mob.”

The bare sentence hit Ann almost like a blow. She had been identifying with Hypatia, she realized, another intelligent woman working in a difficult time. Were they going back to rescue her? No, she would die twenty-four years after the destruction of the library, far too late for them. But at least they might get to meet her.

The next day in class she asked if Strickland had any videos of Hypatia. Strickland frowned for a brief moment, so quickly that Ann was not completely sure she had seen it. “You’ve been doing research, then,” she said.

“Yeah,” Ann said.

“Well, we would have gotten to her eventually. And as it happens we do have a video.”

She called it up on the computer. They saw a group of people talking, gesturing, laughing, mostly men but some women, with a woman at the center. The websites had all agreed that Hypatia had been astonishingly beautiful, but no one would have ever said that about this woman: she was plump, shorter than anyone else in the crowd, her nose squashed in the middle, her eyebrows too heavy. She wore what Ann knew was called a tribon, a rough woolen cloak usually worn by the poor; some philosophers dressed in them too, to show their lack of interest in material things. Her unruly black hair had sprung free of most of the ribbons she had tied it with, and as they watched another ribbon came loose and fell to the ground.

Her face showed a fascination with the debate, a vitality that few of the others had. Her eyebrows arched high on her forehead at something someone had said and then stayed there for the rest of the conversation, making her look perpetually amazed.

When the video ended Strickland summarized the woman’s life for Zach and then said to Ann, “You admire her, don’t you?”

Ann nodded.

“Well, it happens. We all have our favorites, people whose lives we wish had turned out differently. It’s hard, because you can’t tell them anything they don’t already know, including—especially—how they die. You can’t help them in any way, no matter how much you want to.”

Ann nodded again, surprised. Strickland had never volunteered anything so personal during class. She wondered which historical figure the professor had wanted to save.

A few days later Strickland gave them their cover stories. “This time you’re going to be from Crete,” she said, smiling at Ann. “We thought we might as well use your experience from your last trip. Of course in this era Crete has been conquered by the Greeks and then the Romans, so it’s pretty different from what you remember. But the climate’s still the same, and so is most of the food. And the best thing is you probably won’t meet anyone who comes from there—it’s a backwater now, far away from the centers of power. You’re going to be scholars who are visiting the library to study. That’ll give you a reason to be there, but it won’t matter so much if you’re not that sophisticated, if you don’t know a lot about the customs of that tace.”

Zach hadn’t been sent on assignment yet, and when Strickland brought them to the fitting room he looked at the rows and racks of costumes in astonishment. The professor gave Ann a tunic and then what looked like a long blue shirt, so long, in fact, that when she held it up to her neck it dragged along the floor. “The tunic goes on underneath,” Strickland said. “And the extra fabric of the chiton is bundled up over the belt.”

Zach got a tunic, a shorter chiton, and a belt. “Shouldn’t I be wearing a toga?” he asked. “Alexandria was part of the Roman Empire, you said.”

“You’d get more attention than you want, in a toga,” Strickland said. “Only Roman citizens wore them.”

They picked out leather sandals and then went to their changing rooms. It took Ann a while to arrange her clothes the way Strickland had shown her, but finally, when everything was more or less in place, she looked up into the mirror. There was an embroidered band along the neckline and hem of the chiton, a beautiful pattern in red and gold.

She grinned at her reflection. A scholar from Crete, she thought.

Zach spent their free time asking her questions about her trip to Kaphtor. She told him about Gregory’s death, the Minos and the queen, the bull games, their capture and rescue. She tamped down her cynicism, keeping to herself all the questions Meret had raised. Zach deserved to see things for himself, to make up his own mind. And she was still unsure what she believed; she found herself moving from one position to the other within the space of a minute, swinging like a broken needle on a dial from one end to the other.

AND THEN IT WAS time. They got their cheek swabs, and went to the fitting room and put on their clothing. A hairdresser arranged Ann’s hair so that it curled above her forehead and fell straight in back. Another woman hung her with more jewelry than she had ever seen in her life, so much that she felt like a Christmas tree draped with ornaments: a gold necklace with garnets, matching gold earrings, some rings, and a snake bracelet that wound halfway up her arm.

She and Zach and Da Silva and Elias assembled in the launch room, received their bags, stood on the platform, heard the countdown. Colors blurred and then sharpened, and she felt a hard wrench in her stomach that made her double over and almost vomit.

The feeling passed, and she straightened up and looked around her. The others were getting up too, and her first reaction was an intense relief that everyone had come through safely.

They had landed, once again, in place without streets or people. Hard sand stretched all around them, with a few buildings and palm trees in the middle distance.

Elias dug a shallow hole in the ground and buried the key. “This way,” he said.

He set off across the sand and they followed. It should have been hot, as hot as Kaphtor, but Alexandria stood between the Mediterranean and Lake Mareotis, and the breezes that blew between the two of them kept it cool.

Their walking brought them to a temple of white marble with statues standing on either side of the door, an older goddess and a younger one holding sheaves of wheat in their hands. Demeter and Kore, Ann thought. No, they’d call them Ceres and Proserpina hern, the Roman names for them. It lifted her spirits to see them in this new tace, like running into friends in a strange city.

Past the temple was a huge oval structure that she recognized as the hippodrome, and beyond that a city wall and the Canopian Gate. Two guards stood on either side of the gate.

“Open your bags, please,” one of them said. “Did you bring any books?”

They confiscated books from travelers and then copied them, she knew, and returned the copies instead of the originals. Because of that the agents had not packed any books, not wanting to draw attention to them.

The guards looked inside their bags and motioned them through. A street stretched out before them, straight and smooth as a table, lined with columns made of red granite. They passed churches and temples, gardens and obelisks and statues, everything a strange combination of the light classicism of Greece and the ponderous weight of Egypt, so that they saw temples with painted columns in front and carvings of Osiris and Isis on the massive red-brick walls. Other streets crossed theirs at right angles, and she thought that no matter how much she had loved Knossos she was glad to have come to a tace you could map out on a grid. All of it spread out, open, displayed before them like goods for sale.

People passed them too, Roman soldiers on horses and camels, monks in black robes, citizens walking or carried on sedan-chairs, wearing cloaks and chitons and togas. Fortune-tellers sat next to cages filled with birds, offering to cut the birds open and read the entrails. Philosophers stood on the corners, calling out their wares like fruit-sellers: “You there—do you know what the perfect number is?” “What’s the size of the world—have any idea?”

Zach was looking around him, trying not to stare, not to be too obvious. “I know,” Ann said in English. “Isn’t it great?”

A man in front of them stopped abruptly and bowed solemnly to a cat on a doorstep. Zach nodded, seeming too amazed to say anything.

The company liked to get their agents to a tace in late afternoon, giving them time to look around, eat a meal, and have a good night’s sleep before they started on their assignment. They stopped at a restaurant and Ann had a surprisingly good dinner of fish and beer, with figs and melons and raisins on the side.

Elias led them to their inn. Ann was certain she wouldn’t be able to sleep that night, but when she woke up it was morning, the sun shining through their window.

“All right,” Da Silva said at breakfast. They were back at the same restaurant, eating rolls stuffed with fruit and drinking more beer. She was speaking English, though there was no one around to overhear them. “We’re going to give you your assignments. Very simple this time. All you have to do is move some oil lamps in the library from one place to another. We’re going to head over there today, show you where the lamps are and where we want them, and then we’ll go back tomorrow, early in the morning. The disturbances will start tomorrow and spread to the library about an hour later, so we’ll want to be well away by then.”

“What disturbances?” Zach asked.

“I was getting to that. The Christian patriarch here, The-ophilus, is taking over all the pagan temples, turning them into churches. Tomorrow he’s closing the Serapeum, the most important temple in Alexandria, and a group of pagans has vowed to keep it open. They’re going to barricade themselves inside it and fight the patriarch’s forces. And then the fighting spreads to the library, and the patriarch’s mob burns it down.”

“The library’s destroyed tomorrow?” Ann asked. “Isn’t that cutting it a little close?”

“We try to spend as little time in a tace as possible, to minimize errors. You had more time in Crete because we didn’t know how long it would take to gain the Minos’s confidence. This tace, as I said, they’ve given you an easier assignment.”

“When am I going to talk to Meret?” Ann asked.

“I don’t know. I don’t know if there’ll be time. We’ll have to play everything by ear.”

They went out into the streets again. Alexandria was tiny, Ann remembered, only about two miles from east to west and one mile north to south, though it was one of the most important cities in the world.

They turned at the intersection of two main streets, marked by high red columns at the corners, then Elias took them through an outdoor market. She looked for evidence that something was about to happen, for displays of tension or temper, but everyone seemed to be going about their business. People all around them were stopping at booths and chatting to the proprietors, buying olives, lapis lazuli, cinnamon, ivory statues and golden charms in the shapes of gods and goddesses. And of course books—one section of the market was devoted entirely to venders selling scrolls.

How would she know what a normal day in the city looked like, though? Those people over there, whispering to each other, were they pagans discussing their tactics for tomorrow? Would that monk in the black robe take part in the fighting?

They came out on the other side of the market, into a garden the size of a city block. A group of people walked past them along the flowerbeds, talking loudly.

There was something eerily familiar about the scene, like the worst case of déjà vu she had ever had. The people were all leaning in toward the center, listening intently. Then the crowd parted briefly, and she saw a small woman with raised eyebrows.

Hypatia, Ann thought. Not only that, but this was the exact moment she had seen on the video in class. A ribbon came loose from Hypatia’s hair, and as she watched it fell to the ground, forgotten.

She looked around for the camera, found it as it buzzed past them, the camera’s wings glassy in the sunlight. If she watched the video again would she see herself on it this time?

Another woman stood at the outskirts of the group. Ann didn’t remember her from the video; the camera hadn’t photographed that part of the crowd. A black woman, with long black braids mixed with gray …

“Meret!” she said without thinking.

The woman turned toward her. “I’m sorry,” she said in Greek. “Do I know you?”

God, that was stupid, Ann thought. Da Silva and Elias were both staring at her, looking shocked and angry. “I—I saw a video of you back at Transformations,” Ann said to Meret in English. “They told us to find you if we had any problems.”

Meret frowned. “They never said anything to me about being a Preparer,” she said. She caught sight of Elias and grinned. “Yaniel! I didn’t know you’d be here.”

“No, this assignment was planned after you left,” Elias said. “Good to see you.”

“You too,” Meret said. “Hey, what happened to your mustache?”

Elias scowled. “I had to shave it off. It hasn’t grown back yet.”

Meret looked around for Hypatia and her followers, but they had already gone past the obelisk at the center of the garden. “Well, I have my own assignment hern. Where are you staying?”

Elias told her, and she hurried away.

“What were you thinking?” Da Silva asked Ann after Meret had gone. “Didn’t they tell you that she’s never seen you before? That you have to be careful, very careful? The last thing you want is for her to become suspicious.”

It was hard hearing Da Silva criticize her, worse than if it had been anyone else. “I’m sorry,” she said. “It won’t happen again.”

“All right,” Da Silva said, sounding mollified. “You recovered well, at least.”

They headed across the garden toward a cluster of buildings. Excitement began to fill her, a different and more intense excitement than what she’d felt at the palace in Knossos. Here was an entire city that understood the importance of books, of knowledge and ideas and philosophy. And she would see it soon, the largest and greatest library in the world.

They came to the porch and walked between the two statues, Thoth and Seshat. “God of wisdom, and of writing,” Elias murmured, indicating Thoth. “Goddess of time and measurement”—and now Ann saw that what she had thought was Seshat’s staff was some kind of recording instrument, marked with a series of notches. It was topped with a star enclosed in a sort of upside-down bowl, or a crescent moon facing downwards.

The bronze doors stood open. A guard asked them for their proof of membership, and Elias showed him the papers the company had forged. Then Elias led them through an antechamber and into an open courtyard surrounded by columned passageways. They headed down one passage, past people talking, arguing, hurrying from one place to another with buckets of scrolls. Some of the people were head-down in their scrolls, and Ann and the others had to dodge out of their way as they approached.

Doors opened off the colonnade. She glanced through one and then stopped, her breath caught in wonder. The room was enormous. Tall marble columns held up a frieze along the walls, with bookcases in the niches between them. A statue of Minerva stood at the front, the drapes of her clothes swirling as though she had just arrived and planted her spear against the pedestal. Two rows of desks ran down the room, with people sitting at them and reading quietly. Marble of every color paved the floor, shining out where the sun hit it from the high windows and open door: blood red, sea green, fiery yellow-orange.

She took a step inside. The place smelled sour, organic, probably because of all the papyrus scrolls crowded together; it reminded her of a health-food store. She looked up and saw another story above the frieze, with more niches, more bookcases, another statue. And this was just one section of the library, with more rooms elsewhere.

“Ann!” Elias called. “Come on.”

She hurried after them. They passed a large amphitheater, probably an empty classroom, and then a smaller classroom, with young men and a few women sitting on the stone steps and taking notes. Boys and girls sat in the next room, ranging from about five to ten years old, and at the head of the class, pointing to some Roman numbers written on papyrus, was Hypatia, with Meret standing next to her.

Was Meret supposed to be there? What if she refused to follow orders again, what if she was teaching them calculus or Arabic numbers, things that hadn’t even been invented yet?

“Is that what she’s here to do?” Ann whispered to Elias, not wanting Meret to look up and see them. “Teach the kids?”

Elias peered into the classroom. “I don’t know,” he said. “We’d better let her get on with it, whatever it is.”

The line of columns ended and they walked through another garden, this one with a reflecting pool at the center. Then they came to another colonnade, and another row of doors.

Elias consulted a piece of papyrus and went into one of the rooms. This room was small, about a third the size of the first one, but it was arranged along the same plan, with bookshelves and columns and another statue at the front. He pointed to an oil lamp on one of the tables and said, “That lamp there—that has to go on this table here, closer to the bookshelves. Like I said, we’ll do that early in the morning, when the place is nearly empty. We want as few people seeing us as possible.”

He studied them a moment. “Let’s say—Ann, you’re in charge of this one. Now come on and we’ll find the rest of them.”

He looked at the papyrus and headed down the passageway, and they followed. Ann thought of Meret again, wondering what it would be like to work with Hypatia. She felt a dull prick of jealousy at the idea of the two of them becoming friends, especially when her own assignment was so boring in comparison.

And then, perhaps because she was remembering Meret from the graveyard in Knossos, she had a terrible thought. She saw the lamps knocked over, the flames leaping eagerly for the papyrus scrolls. “Why are we doing this?” she asked. “Are we trying to make sure the library gets burned down, or burn down more of it?”

Two clerks hurried by, arguing about where to shelve some scrolls. “Hush,” Elias said, though she had been speaking English. “The librarians get very nervous when people talk about fire. Understandably so.”

“But why do we want to move those lamps?”

“You know we can’t tell you that,” Elias said. “And to be honest, I couldn’t tell you even if I wanted to—they don’t explain things to the Facilitators anymore.”

“Really? Why?”

“I don’t know. It started when we got back from Crete.”

“So they thought the problem was that Meret knew we were supporting the Minos? That if she didn’t know she would have completed her assignment?”

“Maybe. I don’t know.”

But doesn’t that mean they have something to hide? she thought. That if they told us the results of our actions we wouldn’t do them? She said nothing, though. Clearly Elias and Da Silva didn’t want to hear her speculations about the company.

They headed toward other parts of the library. Twice Elias went into rooms and pointed out oil lamps to Zach and Da Silva. Finally he found a lamp for himself, in a part of the library that seemed to be devoted to mending scrolls, and they headed back to the entrance.

The library was starting to close by then; people in Alexandria only worked from morning to early afternoon. It seemed like a good idea to Ann, and she wondered what Sam at the computer shop would have said if she’d told him she wanted to work Alexandrian hours.

“We have the rest of the day off, like the Alexandrians,” Elias said as they went back through the first courtyard. “Unfortunately we’ll have to spend it indoors—the cameras didn’t pick up any fighting today, but they might have missed something.”

Ann had had her fill of waiting at inns. “What about Meret? When am I supposed to talk to her?”

Elias thought a moment. “I suppose you can go look for her now. But be careful, and come back as soon as you can.”