Sometimes, you must harm a person in order to heal them, Layla knew. Still it was hard. There are so many ignorant people in the world, and death is such a harsh penalty for ignorance.

A storm was building, like a toothache, dull right now but promising sharp pain. In an hour or two, lightning would slash across the clouds like whips.

As the ship crossed the breakwater into the bay, sailors let out cheers and sighs of relief. The stone ramparts of a castle rose up to the right, wallsgleaming from a fresh coat of lime. Merchant villages made a cozy sight, nestled along the riverbanks with lamps already lit, though they knew not what they invited.

It always started this way for Layla, her waking in some strange port, or wandering a road, not knowing where she came from or where she would go.

“Preparate l’ancora!” a man shouted nearby. She recognized that tongue. Italia. I come from Italia this time.

A gust of wind blew fierce, giving her a chill, and she drew her black mantle about her, woven from dusk and nightmares.

Layla, my name is Layla, though that is not what the people of this land would call her. They’d grant her a new name when they became aware of her.

But for now, as sailors rushed past her, dropping anchor and preparing to secure the ship for the night, no one seemed aware of her. Sailors in sweat-stained shirts would dance past her as if unaware, neither seeing her nor hearing her soft breathing.

As the ship settled into a sheltered alcove, she crept onto an away boat and sat silently while sailors rowed her to the docks. Seagulls followed the boat in a cloud of white, shrieking their hunger.

At the docks, crowds greeted the shipmates. There were fishermen coming in for the night and dock workers bustling to unload stores. Young urchins raced through the cobbled streets, their cries of delight not unlike those of the gulls, while at cozy inns the courtesans leaned out from balconies in their nightclothes, exposing their wares.

Layla strode through streets that stank of horses and sooty coal fires, and wondered what port she had landed in.

Everyone ignored her. She passed as soundlessly as a wraith, until she saw a baby girl. A pallid little thing with green eyes, strawberry hair, and a somber expression. A fancy sunbonnet was tied over her head, and a bit of snot ran down her nose. She was teething. She gazed right at Layla and reached out a fat fist, as if beckoning.

Layla recognized the child’s vulnerability, and more importantly the child saw her. As it reached toward her, Layla could not resist the summons.

She crept forward and bent near the girl’s head, as if to steal a kiss, not knowing if it would bring death or a gift. The girl looked to be eight months old, maybe nine, with dull eyes.

While the child’s mother, a wealthy woman in a long wool jacket of midnight blue haggled with a street vendor over the price of parsnips in an oak barrel, Layla breathed upon the child.

“Oh, you’re a sweet little thing,” Layla whispered. Her mother made her purchase and began to push the stroller away.

“Come along, Whitley,” the mother urged.

Layla peered into the babe’s eyes, and saw her own visage reflected there, a face plated in bone, black eye sockets, and a grinning skull.

I bring death, this time, Layla thought. I have a name for the child, but I still have no name for myself.

The Great Pestilence swept into London like a fog and blanketed the city like hoarfrost. Kate heard about it everywhere—a town crier walked down her lane ringing a bell and called out the evil news, then a neighbor with a wagging tongue told how the Jews were to blame, then came the old abbott, who advised her to pray to the saints for deliverance.

As a young mother, Kate worried. Whitley was only nine months. Her husband Dale was a woodworker who spent twelve hours a day at the carriage works, building fine carriages for nobles.

She heard rumors of people sweating from chills or wandering the streets in a daze. And one day at the market, a fellow staggered into the street, a seaman in a red-and-white striped shirt, with his beard shaved clean. His eyes were glassy, as if drunk, but she saw a nob on his neck, a boil as purple-black as a large plum, and he begged, “Barber? Can you show me to a barber?”

He stank like death. She pointed down the street to a corner and urged, “Turn left there. Johnny will lance it!”

Then she stepped back and watched him lurch away in horror, heart pounding.

She hurried through the vendors’ stalls and bought enough carrots and onions and apples to last a few days, then grabbed her children and rushed to the safety of her small home.

As she rounded the corner, she glanced down the lane and saw the sailor stumble from the barbershop and fall to the cobblestone street. A woman rushed near, took one close look, and screamed.

Kate drew back in horror and urged her daughter, “Come along.” She didn’t need to see if the man was dead: his chest did not rise and fall, and a puddle of urine escaped him.

That night when Dale came home from work, she had a nice pie cooking for him, with a bit of rabbit and herbs. He told how three men from the carriage works had the pestilence at home. Two had lost children that day, one a wife. Afterward, her husband sat at the table for long minutes, his blue eyes lost in thought, and did not touch a bite.

“What else happened at work?” she finally asked, heart racing for fear he’d been sacked.

He shook his head and bit his lip. “They took me off finishing the carriages today,” he said. Normally he put fine leather cushions on the seats and fit brass lanterns and handles to the outside. “James wants us to build hearses. Seems that there’s a sudden need.”

That night, while nursing Whitley, Kate fretted as she paced the living room. She sang softly in the night:

“Sleep, sleep, my innocent child,

Dream of hillocks green and grottos wild

Fear not the fox bark, nor cry of the crow,

Dream of windflowers, and posies, and gently go.”

The child grew heavy in her arms. The glow from the embers of the fire were still rosy hot but couldn’t warm Kate all the way to the heart.

She laid her daughter down in a bassinet and pulled a blanket over her.

Kate was not from a wealthy family. A lord might have a private physician from Salerno or Paris. Kate couldn’t figure out what she might offer for help, so she gathered a fresh loaf of bread and some sweet-scented candles.

She reasoned that it was better to seek medical advice before she needed it rather than after, and cheaper, too.

Kate tracked Thatcher down in a chapel nine blocks from her house, and found it full of the dead and dying. More learned than a barber or a wise woman, Thatcher was a scholar. He’d studied philosophy under Signore Sanelli, the most esteemed physician in London, and Kate found him near the apse of the church, surrounded by candles. No moon shone through the stained-glass windows.

The sick lay on pews, covered in blankets. Many of them wept and their teeth chattered. Some trembled in fever and one old man called, “Mother, mother!” and reached toward Kate blindly.

The Father was walking down the aisles, stopping sometimes to pray in a comforting drone and anoint the sick as part of the last rites.

On the victims she saw sweaty brows and glazed eyes, trembling bodies. The air stank of death, and she held a kerchief to her nose, one that had been washed in rosewater and dried on a sunny day.

Everywhere, those who tended the ill whispered comments. “He was fine at sunset, now look at him!” “She was a good woman.”

She walked past the priest and stopped briefly, then curtsied and bowed as a sign of respect. He gazed at her with dull eyes and droned “Bless you, child. Go with God.”

“Thank you, Father,” she said hurriedly.

Kate strode up to the apse of the church.

She found Doctor Thatcher in a sweat-stained tunic, cleaning a woman’s infected leg, up near her groin.

Kate stared in horror, for she’d never seen a man touch a woman there. She recognized the patient from her distinctive cloth bonnet—white, with three layers of frills around the front. It was Winona Ayer, the wise woman and midwife who’d supervised Whitley’s birth.

As Thatcher worked, too busy to wipe the sweat from his aging brow, Kate took her handkerchief and dabbed his red eyes. He’d been crying.

Now he roughly scrubbed a lump in the woman’s groin, a boil the size and color of a burnt chestnut. The rag carried a sharp scent—like soured wine.

He scrubbed with a grating sound, and Kate tried to ignore how the old healer’s hands trembled.

He glanced up at her. “Bring your sick in the front,” he said wearily. “I’ll get them. Can’t promise to make it by morning.” Even as he spoke, she saw a woman enter the church, half-carrying, half-dragging a teenage son.

 “I’m not sick,” Kate answered, her stomach fluttering nervously. “I come to learn how to dodge it.”

The doctor continued cleaning, cleared his throat as if to speak, but sweat dribbled down his chin. His patient didn’t cry out or whimper, and the doctor stopped to peer at her, as if to verify she was still breathing.

She gasped a sudden breath, and the doctor rubbed at her wound until bloody pus oozed out. “There we go,” he said in relief, and tossed the messy rag aside.

He glanced at Winona. “Let it drain for a while, take the swelling down. It might even let the illness escape your body.” He covered her modestly with her skirt, then turned to Kate. “Everything happens for a reason, Kate,” he explained. “We don’t know the reasons. Even illness has a cause. The pestilence was brought on a ship, and when its crew spread through town, the illness came with it.”

“Some think,” he huffed with fatigue, “you only need to look into the eyes of one who has it, and it enters through the eyes. Others think it comes with the stale air.”

A shiver ran over her back. There had been a driving storm three days ago, and rain, but now the cold fog hung over London, and the smell of woodsmoke and coal fires combined with the fog so badly, one could hardly breathe.

“I think it’s bad vapors. In air like this,” Thatcher warned, “the Pestilence spreads fast.”

Kate peered at him in terror. “There must be something we can do.”

“Vinegar,” he advised. “At the first sign of a lump, wash the skin with vinegar, and leave it on. Wine works too, though not as well, and it draws flies.”

She felt hopeful. “Can we wash in it before the plague comes?”

He nodded. “It can’t hurt. And if you dip a rag in vinegar and hold it over your face to breathe when you are forced to go out…”

She nodded, and peered at him, hoping for more counsel.

“It could help,” he warned. “It’s the latest research from Italy. But if I were you, I’d leave the city.”

 She’d already seen people fleeing at night with little more than packs on their backs and bags in their hands. She nodded mutely. She didn’t want to go in winter, not with a child.

“Go soon. Every night in this city is a risk. Don’t travel with others. They’re carrying it with them as they go,” he warned. “They’ll spread it everywhere. Stay out of inns. It would be better to sleep under the trees, if you must. And go somewhere safe.”

She considered. Dale’s parents lived in Banbury, on a small estate two miles from the castle. She didn’t know them well. She remembered the green hills, dotted with sheep, and fishing beside a lazy river beneath sprawling willows whose leaves twisted in the slightest breeze, flashing green and white, green and white.

“Now,” Thatcher said, “if you’ll excuse me.”

She pulled out her fresh bread and candles, handed them to the doctor. He looked as if he might give them back, then glanced at the huddled people dying all around, and gave a heartfelt thanks.

Kate would have rushed home, but just outside the church, a strange old woman whose face was hidden by a hooded cloak grabbed her, put something round and hard, like a coin, in her hand.

“’Ere, love, put this under yer pillow!”

Kate glanced down. It was a heavy amulet made of bronze. It showed a worn god’s eye inside a pyramid on one side, and Hebrew, Latin, and Egyptian names were printed on the back: Lilith, Hecate, and Isis.

This was old magic, and she clutched the amulet in her fist, afraid to be seen by the priest with it, but even more afraid to throw it away. She took it home and put it under her daughter’s blanket in her bassinet before she washed the child with vinegar.

Layla found the old stone home with its new thatch roof and flower boxes filled with dead stems and knew that the babe was inside. She stood on the street at dawn with wisps of fog swirling around her. There were no streetlightsstreet lanterns, but a thin crescent moon shone down.

It had been only a few days since Layla had touched Whitley, and she’d come to collect the child’s soul, but she hesitated outside, peering at the smoke curling from the chimney in consternation.

She tried to push her way into the house, but it felt as if bars sealed her out. Something blocked her way.

Whitley was hers by right.

Layla bent her head, tried to force her vision forward, to see the child.

The mother had set barriers: magical spells and prayers from a priest. Neither spells nor prayers were likely to do much good. Kate’s ancestors had dug up the bones of saints and burned them, offering prayers on the smoke as it rose, but even such entreaties availed little.

There was something else—the vinegar. The acid in it was strong enough to clean tarnish from silver, and it was strong enough to kill germs and viruses. Layla did not know who had sent her, but she believed that if it had not been a god, at least the gods allowed her to continue her work.

The plagues didn’t just bring death. The viruses often inserted DNA into their hosts. Three million years ago, a splice had caused the size of the human brain to double in the succeeding generation. Two million years later, a similar virus had caused the brains of humans to double again and split into two hemispheres.

Though Layla brought death to some, she brought growth and change to others. If humans would just study her secrets, they’d see that she brought not misery, but the keys to understanding.

Kate’s vinegar thwarted the work. It was enough to block Layla.

Give it time, Layla thought, pushing with all her will. The woman will not always be vigilant.

Besides, there were other ways in.

Kate woke to find the house roasting. She’d been asleep comfortably beneath a quilt when she became aware of it and thought back groggily. The baby had cried, and Dale had told her to sleep. That had been an hour ago, when the house was nippy. Now it was an oven.

She turned in the gloom to see Dale rocking by the fire, cuddling with his daughter. He held her sleeping form, combed back her curls with a finger, and kissed her on the eyes.

That’s when Kate saw it: a sheen of sweat on his forehead. He shook just a bit. Tremors.

She climbed out of the bed as swiftly as she could and raced to Dale, grabbed the babe from his hands, and pulled her to safety.

He peered at her, eyes yellowed and glazed, and she saw the purpling bruises at his throat, on both sides of his neck.

“I’m sorry,” he said.

“You’re ill,” she corrected. But she knew that many people thought the pestilence was sent by God as a punishment for man’s sins, and now she wondered if he needed to confess. She rushed Whitley to her cradle, grabbed her bottle of vinegar and a rag, and went to her husband. She poured and began to wash his neck as she spoke. “What are you sorry for? Shall we get you to a priest?”

Dale blinked as if to hide tears and shook his head. “Sorry I’m sick.”

Dale was a lusty man. He’d made love to her just last night, and she’d fallen asleep entangled in his arms. She knew that other women fancied him. She could see it in the way their eyes followed him when he walked down the street.

“There have been no other . . . girls?”

He chuckled dismissively. “No, you’re the only one for me—you and Whitley.”

She looked up into his face, not knowing if she should dare. If she peered into his eyes, would she catch his disease? They’d lain close together all night, kissing one another, sharing their air, two sweaty bodies in love.

Somehow, she knew that if she was going to get ill, there was no stopping it. Her insides quivered, and her heart raced. She kissed him on the lips. “Then you’ve nothing to fear. You pay our tithes, say your prayers. If you live, you’ll live unto god, and if you die, you’ll die—”

“Unto god,” he said with her.

He put a finger to her lips. “Listen, Kate, if I don’t make it, you must go to my parents’ house.”

“No—you’ll be fine,” she interjected.

“Listen, they’ll take good care of you.”

“I wouldn’t want to be a burden,” she said. She was afraid. She didn’t want to show up on their doorstep, a strange woman they’d met only once, with a baby. Two mouths to feed!

But Dale shook his head, and she took her cloth and wiped the sweat pouring down his face.

“You’ll not be a burden. My mother would love to have you near. They’ll both love you as I do.”

“No one loves having two mouths to feed.”

He shook his head. “My grandfather was a Knight Templar. After the knights were betrayed, he went underground, changed his name. He’s wealthier than he lets on—wealthy enough to care for a couple more mouths.”

Kate didn’t know what to think of that. Some said that the Knights Templar were heretics and thieves. Others said they were god’s own warriors, that they’d kept the roads free of highwaymen all the way to Jerusalem so that penitents could travel in peace. It was only the greed of an evil French king that had betrayed them.

She thought back on Dale’s father. A man with kind blue eyes and silvering hair that fell in waves. She couldn’t imagine him having an ounce of evil in him.

Living on the estate would be heavenly. She imagined sunshine on a lazy river, running with her daughter through meadows filled with daisies.

She dared not dream of it. There was too much work to do, helping Dale get better.

She made him a quick breakfast of toasted bread with jam and honey, but by the time she was finished with it, Dale had fallen back in his chair, mouth open.

He spoke little over the next hour, besides telling her over and over, “I love you. I’ve always loved you. Tell Whitley for me…”

She took off his shirt to wash him further, found an abscess growing under his right arm, as well as the two on his neck. But he was young and strong, she reasoned, and if anyone would recover, her beloved husband would.

So she prayed under her breath and scrubbed him clean over and over. He fell into a high fever and swooned.

The day had hardly begun before he passed.

She wrapped him in a blanket and hitched her hands beneath his arms, then pulled him out the door.

She considered what the priest had told her: to flee this plagued city. Dale had agreed, urging her to go to his parents’ home, some thirty leagues down dirt roadways. It would take weeks to get there, if she made it at all. I’ll have to avoid the hostels and sleep out in the rain. Winter is coming on already. I’ll be hungry and footsore before I reach our new home—if I don’t come down sick myself.

She packed a few clothes, all her money and a bit of food, grabbed the baby, and began pushing her little stroller north.

As she passed down the roads of London, between cramped houses, she felt like a wraith. The roads were empty this morning. Everyone in the city seemed to be in hiding.

All she saw were a few street urchins, more than she recalled seeing in the past. Some were snot-nosed kids no older than four, and many of them followed her with their eyes, hungrily.

Some even called out for food, but she dared give them nothing.

As Kate passed, one little brown-haired girl complained, “Mumma and Pappa died.” Kate could do nothing for the waif.

She hiked the upland road all day, and by noon was out of the London fog and into the bright autumn forests where the leaves of maples and alders were going gold and scarlet. She found herself overtaking other travelers in her haste.

At midday she saw a burly old man with a bowl-cut shave walking down the street with no shirt and a bloody back, crying, “Repent! Repent of your blasphemies and whoredoms!”

With each cry of “Repent!” he would slap himself with a cord that cracked like lightning and left a weal of blood.

She repented of any blasphemies she might have committed, any evils she’d ever thought, and slept that night under a sprawling oak, dripping with holly. It was a cold night with piercing stars and no moon, but blanketed by fallen leaves, she managed to keep her babe warm.

Her milk dried up on her third day out. It didn’t matter. Whitley had begun coughing in the night, and by dawn, the chills were on her. The babe’s neck swelled so badly, she struggled to draw a breath, and when she didn’t cry, she spat up milk, and then stomach acid.

Kate prayed and washed her babe over and over until the very end. It was a relief when Kate finally laid her babe in the ground, atop the bronze amulet.

Kate’s heart swelled with unshed tears as she sat in a daze by the roadside, wondering what to do now. It would be easier to travel without a child, but what would Dale’s parents think when she showed up at their door? Would they welcome her into their own private little paradise?

She imagined the fine meals she would have there, and recalled the joy she’d felt fishing for salmon with willow poles, laughing beside the river.

Then she climbed to her feet and trudged back to London and picked up a familiar brown-haired girl, one of thousands that would need caring for.

The gray lady took Whitley’s spirit by the hand and led her away, smiling.

In time, women like Kate would begin to unravel Layla’s gift. She’d come not to destroy the world, but to challenge it. Only by fighting her would they learn their own potential, begin to unravel their own DNA, learn to increase their intelligence and lifespans.

In time they would slay her. Layla looked forward to that day.