SHE CHOSE A DIRECTION and began to walk, staring around her in disbelief and horror. Shattered pieces of marble lay on the ground, weeds growing up around them. She passed a painted marble arm, then saw the rest of the statue lying a few feet away.

Had she been knocked unconscious, awakening after the mob had done its work? But the place felt different somehow, as though she had been moved through space, or through time.

How could that have happened, though? She hadn’t been anywhere near the key Elias had buried. Da Silva had said that the fifth floor could insert and extract people, so perhaps they had rescued her from the mob. But whern was she, and why hadn’t the company brought her back to her own tace?

She continued on, coming to a field choked by shrubs and briars, and she picked her way through it carefully. After that came a line of fallen columns next to a marble passageway, weeds pushing their way up through the cracks. It looked familiar, and she realized it had been one of the colonnades in the library. She was still at the library, then, but sometime after the destruction.

Her head throbbed, and when she reached back to touch it she felt a lump the size of her thumb. That’s right—she’d been hit with a rock, just before ending up here. And now that she’d noticed it it seemed worse, as insistent as a drum pounding in her ear.

Another statue lay on its back ahead of her, smashed into a dozen pieces. Its head remained whole, though, and she recognized it as Minerva, the statue from the Great Room. Her broken staff lay on the ground next to her.

The entrance had to be around here then, somewhere ahead. She went forward as quickly as she could and came to the door of the antechamber. The roof had fallen in in places, and the room was choked with wood and marble and waterlogged papyrus.

She backed out and tried to walk around it, but the space between this building and the next was littered with wreckage, blocking it in all directions. Huge shaggy trees had grown up on the pathways. She worked her way forward and back, trying to break through the rubble, her frustration growing.

The sun was directly overhead by the time she made it outside. The garden in front of the library was still there, she saw, and so were the statues of Seshat and Thoth in their niches, chipped and faded but still whole. It was strange to see them like that, in the midst of all the destruction, looking like the survivors of an apocalypse.

People were walking through the garden, or sitting and eating and talking. She hurried forward, brushing off dust and leaves and cobwebs, hoping the places where she’d torn her clothes weren’t too visible. “Excuse me,” she said to a man walking toward her on the path.

“Can I help you?” the man said.

Too late, she realized she had no idea of what she was going to say. She thought quickly. “Do you know—do you know who’s the patriarch now?”

The man looked at her strangely but said, “Patriarch Cyril.”

“For how long?”

The man thought. “Three years. That’s right, it was just around the time I had that rotten tooth, and there was fighting in the streets and I couldn’t get out to have it pulled. They were fighting for Timothy, but if you ask me Cyril’s done a wonderful job. It’s about time we showed those pagans what the true religion is. Theophilus was a good man, God rest him, but he’d been too easy on them.”

She’d been afraid of that. Hypatia had been killed in the third year of Cyril’s tenure. Was that why she’d been brought here, did someone want her to save Hypatia? But who? The company wouldn’t have sent her here without thorough training, she knew that much.

She left the man and continued on to the outdoor market. That at least had stayed the same, crowded and smelling of a dozen spices. People were studying her strangely, though, and looking down she saw that her chiton was still smudged with dirt and soot.

She had no money with her—the Facilitators were in charge of that in the taces they visited—but she was wearing necklaces and bracelets she could sell. She glanced around for a booth selling jewelry.

Now she saw that she’d been wrong before; the market had changed, though in subtle ways. A group of men in black robes stood at the edge, watching the crowd from beneath their hoods: Nitrian monks, called from their desert monastery to help Cyril in his campaign against the Jews and pagans. Soldiers rode past on horses and camels. The scroll merchants were gone, and so were the people who sold charms and statues of gods and goddesses, replaced by men selling crosses. Most of the people here were men, in fact; there were few women on the streets. Maybe that was why everyone staring at her, maybe it had nothing to do with her clothes.

What had that man said, that Theophilus had been too easy on the pagans? Theophilus had been the one to close down the Serapeum, and to order the library destroyed. It was hard to imagine what more he could have done to satisfy the Christians.

She went up to a booth selling jewelry and bargained with the stall-holder for one of her rings, then took the money he gave her to another booth displaying clothes. She changed behind the booth, leaving her old chiton where it dropped.

Now what? She should go back to the inn, see if the others had been transported here as well—that is, if the inn still existed twenty-four years later. And she hadn’t eaten since breakfast, and her hunger along with the pain in her head was making her feel sick to her stomach.

She stopped at a restaurant and ordered roast goose. She hadn’t asked that fanatic in the marketplace what month it was—he would have really thought her crazy if she’d done that, might have even reported her to the authorities—but it had been chilly outside, almost wintry. Hypatia had died in March.

Maybe it was December, maybe she was too late. But she felt strangely certain that Hypatia was alive.

She finished the goose and went back into the streets. The city had changed here as well, she saw: some of the columns had fallen and not been replaced, and every block held a derelict building or two, burned out by fire or broken into. A soldier wearing armor made of bronze plates studied her from a camel, and she felt suddenly conspicuous, though she didn’t think she had violated any laws.

What had the others thought when she hadn’t returned? Had the company started looking for her? Maybe she could find a camera, wave at it, scream, jump up and down. But there probably weren’t any cameras hern; the company only sent them to the taces they called hinges, times and places that existed at some branching of history, where they could mold events into the shapes they wanted.

It didn’t seem likely that they’d find her, out of all of history. She would have to stay hern. And do what? Unlike most of the people in the city she could read and write, but the Christians seemed to disapprove of women who worked. And she would not marry any of these men, not for anything.

No, she had to have come hern for a reason. Maybe once she saved Hypatia she would be rescued, picked up by whoever had sent her. She had to think so, anyway; unlike Meret, she didn’t think she could bear to live outside of her own era.

The inn was still there. She went inside with relief and found the innkeeper, a middle-aged man with a fringe of hair around his head. “I’m supposed to meet my friends here,” she said. “Three people from Crete, like me. Their names are Yaniel and Amabel and Zach.”

He scowled. “Outlandish names you have. No, there’s no one like that here.”

“Are you sure? Zach is young, my age, and—”

“Believe me, I’d remember.”

Maybe they’d used different names. But that was wishful thinking, she knew; there was no reason they should have. They would have wanted her to find them.

She hadn’t realized how much she’d been hoping to meet them here. But she had to push aside her despair; she had work to do.

“I’ve been traveling,” she said. “I wonder—could you tell me what day it is?”

He looked at her disdainfully, though whether it was because she had lost track of time or because she was a woman on her own she couldn’t tell. “The twenty-fourth of March,” he said.

She was right, then. Hypatia had died—would die— tomorrow, on the twenty-fifth. She remembered it because, ironically, it was the date they celebrated the vernal equinox in Hypatia’s era. “I’d like a room for a night,” she said.

He took her money—nearly the last of it, she shouldn’t have splurged on that goose—and assigned her a room.

As she turned away she realized suddenly that this was the innkeeper’s son, the young man who had talked and joked with them twenty-four years ago. The eyes still looked the same, and some of the lines of the face, but sometime over the years he had turned sour, like others she had seen in the city.

Well, it was a good thing he hadn’t remembered their names from their previous visit. It would have been hard to explain why she hadn’t aged in nearly a quarter of a century.

She found the room, went inside, and tugged the latch into place. A scratched and wavy mirror lay next to a washbasin, and she looked into it. No wonder people had stared, she thought. Dirt streaked her face, and a great cobweb draped the top of her head like a hairnet, leaves and rocks caught in it like jewels. She brought the mirror closer to study her pupils, worried about concussion, but it was too distorted for her to see them clearly.

It was still afternoon, but she felt as if she had been awake for the full twenty-four years. And she still had to find Hypatia, and warn her if she could. She washed herself with water from the basin and headed outside.

As she walked through the streets she remembered something Meret had told her: “If you’re ever in trouble and there’s a temple to a goddess, whatever her name is, go there and see if they can help you.” But though she looked for them she didn’t see temples to any goddess, Kore or Demeter or Isis; they had all been burned or converted to churches.

She found Hypatia’s street easily, and the house she had visited with Meret. Just yesterday, according to her internal clock—and it had been only this morning when Theophilus’s men had burned the library.

She knocked at the door, and a woman she didn’t recognize came to answer it. “Does Hypatia still live here?” she asked.

The woman drew back as though Ann had thrown hot water on her. “There’s no one by that name in this house,” she said. She started to close the door.

“Do you know where she went?”

The woman studied her through a crack in the door. “I didn’t even know she’d lived here. It’s that witch you mean, isn’t it? The astrologer?”

“Witch?”

“That’s what Patriarch Cyril said she is. He preached a sermon against her just last Sunday, two days ago. If you do know her I’d suggest you don’t spread it around.”

“She isn’t a witch.”

“Oh, and you know theology better than our patriarch, I suppose. Well, I have things to do. Don’t come back here, or I’ll call the Parabolans.” The Parabolans had started as a group of young men who did charity, Ann knew, but Cyril now used them as an army, to enforce his edicts.

The woman slammed the door. Now what? She could look for Hypatia, though she had no idea where to find her. Or she could go to the Church of St. Michael, where Hypatia would be killed tomorrow.

Her head was throbbing, and she wanted nothing more than to go to sleep—though she knew that if she did have a concussion it could be the worst thing for her. Still, she found herself heading back to the inn. Her thoughts were fraying, becoming confused, and she began to worry that Walker would be waiting for her, and that she had to come up with some story about where she’d been.

But when she got back to the inn she saw with relief that Walker wasn’t there. She went to her room and fell asleep.

SHE WOKE TO LOUD chanting from the street. She stood, disoriented, and went outside. The sun was rising, its bright light lancing down the wide boulevards.

The chanting grew stronger; it sounded as if the mob had taken Hypatia already, or were just about to. She cursed herself for oversleeping, for missing what might be her only chance.

She could hear what the people were shouting now, along with the sound of their feet marching in step: “Witch! Witch! Witch!” The words echoed through the streets, making it impossible to tell where they were coming from.

She hurried to the Church of St. Michael. Her head pounded as she ran; it felt as if someone were trying to drill through it. Halfway to the church she was stopped by the crowd, black-robed Nitrian monks and ordinary men and women from the city, fathers carrying their children on their shoulders, all of them shouting, their faces twisted with hatred.

Men on horses rode among them, wearing the black dress of the priests. She looked around for Cyril and saw a bearded man in a chariot wearing a black robe and hood, shouting something to someone further up. Massy golden jewelry glinted on his chest in the sunlight.

She joined the crowd and eeled her way to the front. Finally she saw a group of young men a few feet ahead of her, the Parabolans. She thought that they had to be holding Hypatia, but they moved in such tight formation that she couldn’t see her. Next to them marched a skinny man in a dirty chiton, his long hair and beard matted. Peter the Reader, the history books said his name was, a minor clergyman.

She struggled to reach the Parabolans, but the crowd pressed in on her, holding her back. Someone shoved an elbow into her stomach, and she nearly vomited.

When she straightened she saw that she had ended up next to Peter. “Witch! Witch! Witch!” he cried, his face distorted. Strings of saliva ran between lips.

Finally the crowd came to two great obelisks. They were the only things that remained from the Caesarium, a temple built by Cleopatra to honor Julius Caesar; the rest had been torn down to build the church. St. Michael, like nearly every church in this tace, was a simple rectangle faced with limestone.

The Parabolans went inside. The rest of the mob followed, crowding in at the entrance and pushing their way through. She was thrown against Peter, briefly smelling his foul unwashed clothes, then squeezed past him.

Four rows of columns headed toward the front of the church. The Parabolans marched down the aisles and flung Hypatia down on the mosaic floor before the altar. Her clothes were torn, her breasts exposed, and she was bleeding in half a dozen places.

Ann watched in horror, a cold current running through her. She had read about this, of course, but reading it was very different from seeing it enacted in front of you. You didn’t hear the voices of hundreds of people, all of them crying out for blood. You didn’t smell their sweat, their clothes, the wine they had drunk and the food they had eaten. You didn’t see the satisfaction on their faces as they stared at Hypatia, helpless at last.

No, not helpless. She regarded her captors with composure, almost smiling, as though she were standing in front of her students and about to begin a lecture on mathematics. “What do you have to say for yourself, witch?” Cyril asked.

“Nothing—I have nothing to say,” she said. “You all know my philosophy, know that I have no argument with Christianity. And if you don’t understand that, then nothing I say now will make any difference.”

Cyril turned to the crowd. “You all heard her—she has no defense for her actions.” He looked back at her. “Will you at least confess your wickedness, and die with a clear conscience?”

“I’ve done nothing wrong.”

“Nothing! You’ve worked your black arts in this city, luring your followers to you by witchcraft. Do you call that nothing?”

“My students follow me of their own free will.”

“Nonsense. No decent person could possibly believe your filthy heresies.”

“Hundreds of them do, though. You’ve seen them.”

Ann slipped back into the crowd. Some historians had claimed that Cyril’s attack on Hypatia had been motivated by jealousy, by the fact that she had more followers than he did, was more beloved by the citizens of Alexandria. Now she was alluding to those followers, and from the little Ann had seen of Cyril she knew he would not stand for it.

“They follow you because of witchcraft!” he shouted, his voice shrill. “How many times do I have to explain that to you? You’re a woman, you can’t understand theology, so the only reason—the only reason—you have any students at all is because you’ve bewitched them.”

A man next to Ann found a pottery jug, communion wine probably, and lifted it to his lips. Someone bumped into him and the jug fell to the floor and shattered.

Ann turned and struggled toward the entrance. She knew what was going to happen now, had read about it in any number of history books, and she knew she could not bear to watch it.

Hypatia said something, but Cyril cut her off. “I’m not going to waste my time arguing with you. And cover yourself at least, witch. Or are you lost to all modesty?”

“Your thugs were the ones who tore my clothes. Let them see what they’ve done.”

Ann had moved far enough away that she could no longer see the two of them. Cyril must have made some gesture, though, because the men around her picked up the broken shards of pottery and surged forward. Ann pushed against them but she was carried along by the sheer tide, back toward the altar.

Someone screamed. The men with shards had reached Hypatia, were scraping her skin from her body. Another jug of wine smashed. The screams rose, grew louder. Ann closed her eyes.

“Too much for you, girlie?” someone asked her. “Why don’t you want to see it? You a witch too?”

She opened her eyes quickly and saw a man leering down at her. She stamped down hard on his instep and hurried away.

He cried out in pain. “Hey, come back, girlie!” another man shouted after her. “You need to see this, see what happens to witches!”

She pushed and jabbed her way through the mob, desperate to get out. Two or three of the others were hurrying as well, unable to bear the screams.

The crowd grew sparser as she reached the back of the church. Finally she saw the door ahead of her, the sunlight beyond it. She ran outside and vomited on the ground.