Matthew came to col ect me after lunch-the only creature among the human readers in the Selden End. While he walked me under the ornately painted exposed beams, he kept up a steady patter of questions about my work and what I'd been reading.

Oxford had turned resolutely cold and gray, and I pul ed my col ar up around my neck, shivering in the damp air.

Matthew seemed not to mind and wasn't wearing a coat.

The gloomy weather made him look a little less startling, but it wasn't enough to make him blend in entirely. People turned and stared in the Bodleian's central courtyard, then shook their heads.

"You've been noticed," I told him.

"I forgot my coat. Besides, they're looking at you, not me." He gave me a dazzling smile. A woman's jaw dropped, and she poked her friend, inclining her head in Matthew's direction.

I laughed. "You are so wrong."

We headed toward Keble Col ege and the University Parks, making a right turn at Rhodes House before entering the labyrinth of modern buildings devoted to laboratory and computer space. Built in the shadow of the Museum of Natural History, the enormous redbrick Victorian cathedral to science, these were monuments of unimaginative, functional contemporary architecture.

Matthew pointed to our destination-a nondescript, low- slung building-and fished in his pocket for a plastic identity card. He swiped it through the reader at the door handle and punched in a set of codes in two different sequences. Once the door unlocked, he ushered me to the guard's station, where he signed me in as a guest and handed me a pass to clip to my sweater.

"That's a lot of security for a university laboratory," I commented, fiddling with the badge.

The security only increased as we walked down the miles of corridors that somehow managed to fit behind the modest façade. At the end of one hal way, Matthew took a different card out of his pocket, swiped it, and put his index finger on a glass panel next to a door. The glass panel chimed, and a touch pad appeared on its surface.

Matthew's fingers raced over the numbered keys. The door clicked softly open, and there was a clean, slightly antiseptic smel reminiscent of hospitals and empty professional kitchens. It derived from unbroken expanses of tile, stainless steel, and electronic equipment.

A series of glass-enclosed rooms stretched ahead of us.

One held a round table for meetings, a black monolith of a monitor, and several computers. Another held an old wooden desk, a leather chair, an enormous Persian rug that must have been worth a fortune, telephones, fax machines, and stil more computers and monitors. Beyond were other enclosures that held banks of file cabinets, microscopes, refrigerators, autoclaves, racks upon racks of test tubes, centrifuges, and dozens of unrecognizable devices and instruments.

The whole area seemed unoccupied, although from somewhere there came faint strains of a Bach cel o concerto and something that sounded an awful lot like the latest hit recorded by the Eurovision song-contest winners.

As we passed by the two office spaces, Matthew gestured at the one with the rug. "My office," he explained.

He then steered me into the first laboratory on the left.

Every surface held some combination of computers, microscopes, and specimen containers arranged neatly in racks. File cabinets ringed the wal s. One of their drawers had a label that read "<0."

"Welcome to the history lab." The blue light made his face look whiter, his hair blacker. "This is where we're studying evolution. We take in physical specimens from old burial sites, excavations, fossilized remains, and living beings, and extract DNA from the samples." Matthew opened a different drawer and pul ed out a handful of files.

"We're just one laboratory among hundreds al over the world using genetics to study problems of species origin and extinction. The difference between our lab and the rest is that humans aren't the only species we're studying."

His words dropped, cold and clear, around me.

"You're studying vampire genetics?"

"Witches and daemons, too." Matthew hooked a wheeled stool with his foot and gently sat me on top of it.

A vampire wearing black Converse high-tops came rocketing around the corner and squeaked to a halt, pul ing on a pair of latex gloves. He was in his late twenties, with the blond hair and blue eyes of a California surfer. Standing next to Matthew, his average height and build made him look slight, but his body was wiry and energetic.

"AB-negative," he said, studying me admiringly. "Wow, terrific find." He closed his eyes and inhaled deeply. "And a witch, too!"

"Marcus Whitmore, meet Diana Bishop. She's a professor of history from Yale"-Matthew frowned at the younger vampire-"and is here as a guest, not a pincushion."

"Oh." Marcus looked disappointed, then brightened.

"Would you mind if I took some of your blood anyway?"

"Yes, as a matter of fact." I had no wish to be poked and prodded by a vampire phlebotomist.

Marcus whistled. "That's some fight-or-flight response you have there, Dr. Bishop. Smel that adrenaline."

"What's going on?" a familiar soprano voice cal ed out.

Miriam's diminutive frame was visible a few seconds later.

"Dr. Bishop is a bit overwhelmed by the laboratory, Miriam."

"Sorry. I didn't realize it was her," Miriam said. "She smel s different. Is it adrenaline?"

Marcus nodded. "Yep. Are you always like this? Al dressed up in adrenaline and no place to go?"

"Marcus." Matthew could issue a bone-chil ing warning in remarkably few syl ables.

"Since I was seven," I said, meeting his startling blue eyes.

Marcus whistled again. "That explains a lot. No vampire could turn his back on that." Marcus wasn't referring to my physical features, even though he gestured in my direction.

"What are you talking about?" I asked, curiosity overcoming my nerves.

Matthew pul ed on the hair at his temples and gave Marcus a glare that would curdle milk. The younger vampire looked blase and cracked his knuckles. I jumped at the sharp sound.

"Vampires are predators, Diana," Matthew explained.

"We're attracted to the fight-or-flight response. When people or animals become agitated, we can smel it."

"We can taste it, too. Adrenaline makes blood even more delicious," Marcus said. "Spicy, silky, and then it turns sweet. Real y good stuff."

A low rumble started in Matthew's throat. His lips curled away from his teeth, and Marcus stepped backward.

Miriam placed her hand firmly on the blond vampire's forearm.

"What? I'm not hungry!" Marcus protested, shaking off Miriam's hand.

"Dr. Bishop may not know that vampires don't have to be physical y hungry to be sensitive to adrenaline, Marcus."

Matthew control ed himself with visible effort. "Vampires don't always need to feed, but we always crave the hunt and the adrenaline reaction of prey to predator."

Given my struggle to control anxiety, it was no wonder Matthew was always asking me out for a meal. It wasn't my honeysuckle scent that made him hungry-it was my excess adrenaline.

"Thank you for explaining, Matthew." Even after last night, I was stil relatively ignorant about vampires. "I'l try to calm down."

"There's no need," Matthew said shortly. "It's not your job to calm down. It's our job to exercise a modicum of courtesy and control." He glowered at Marcus and pul ed one of the files forward.

Miriam shot a worried glance in my direction. "Maybe we should start at the beginning."

"No. I think it's better to start at the end," he replied, opening the file.

"Do they know about Ashmole 782?" I asked Matthew when Miriam and Marcus showed no sign of leaving. He nodded. "And you told them what I saw?" He nodded again.

"Did you tel anyone else?" Miriam's question to me reflected centuries of suspicion.

"If you mean Peter Knox, no. Only my aunt and her partner, Emily, know."

"Three witches and three vampires sharing a secret,"

Marcus said thoughtful y, glancing at Matthew. "Interesting."

"Let's hope we can do a better job keeping it than we have done at hiding this." Matthew slid the file toward me.

Three sets of vampire eyes watched me attentively as I opened it. VAMPIRE ON THE LOOSE IN LONDON, the headline screamed. My stomach flopped over, and I moved the newspaper clipping aside. Underneath was the report of another mysterious death involving a bloodless corpse.

Below that was a magazine story accompanied by a picture that made its contents clear despite my inability to read Russian. The victim's throat had been ripped open from jaw to carotid artery.

There were dozens more murders, and reports in every language imaginable. Some of the deaths involved beheadings. Some involved corpses drained of blood, without a speck of blood evidence found at the scene.

Others suggested an animal attack, due to the ferocity of the injuries to the neck and torso.

"We're dying," Matthew said when I pushed the last of the stories aside.

"Humans are dying, that's for sure." My voice was harsh.

"Not just the humans," he said. "Based on this evidence, vampires are exhibiting signs of species deterioration."

"This is what you wanted to show me?" My voice shook.

"What do these have to do with the origin of creatures or Ashmole 782?" Gil ian's recent warnings had stirred painful memories, and these pictures only brought them into sharper focus.

"Hear me out," Matthew said quietly. "Please."

He might not be making sense, but he wasn't deliberately frightening me either. Matthew must have had a good reason for sharing this. Hugging the file folder, I sat down on my stool.

"These deaths," he began, drawing the folder gently away from me, "result from botched attempts to transform humans into vampires. What was once second nature to us has become difficult. Our blood is increasingly incapable of making new life out of death."

Failure to reproduce would make any species extinct.

Based on the pictures I'd just seen, however, the world didn't need more vampires.

"It's easier for those who are older-vampires such as myself who fed predominantly on human blood when we were young," Matthew continued. "As a vampire ages, however, we feel less compulsion to make new vampires.

Younger vampires, though, are a different story. They want to start families to dispel the loneliness of their new lives.

When they find a human they want to mate with, or try to make children, some discover that their blood isn't powerful enough."

"You said we're al going extinct," I reminded him evenly, my anger stil simmering.

"Modern witches aren't as powerful as their ancestors were." Miriam's voice was matter-of-fact. "And you don't produce as many children as in times past."

"That doesn't sound like evidence-it sounds like a subjective assessment," I said.

"You want to see the evidence?" Miriam picked up two more file folders and tossed them across the gleaming surface so that they slid into my arms. "There it is-though I doubt you'l understand much of it."

One had a purple-edged label with "Benvenguda" typed neatly on it. The other had a red-edged label, bearing the name "Good, Beatrice." The folders contained nothing but graphs. Those on top were hoop-shaped and bril iantly colored. Underneath, more graphs showed black and gray bars marching across white paper.

"That's not fair," Marcus protested. "No historian could read those."

"These are DNA sequences," I said, pointing to the black-and-white images. "But what are the colored graphs?"

Matthew rested his elbows on the table next to me.

"They're also genetic test results," he said, drawing the hoop-covered page closer. "These tel us about the mitochondrial DNA of a woman named Benvenguda, which she inherited from her mother, and her mother's mother, and every female ancestor before her. They tel us the story of her matrilineage."

"What about her father's genetic legacy?"

Matthew picked up the black-and-white DNA results.

"Benvenguda's human father is here, in her nuclear DNA- her genome-along with her mother, who was a witch." He returned to the multicolored hoops. "But the mitochondrial DNA, outside the cel 's nucleus, records only her maternal ancestry."

"Why are you studying both her genome and her mitochondrial DNA?" I had heard of the genome, but mitochondrial DNA was new territory for me.

"Your nuclear DNA tel s us about you as a unique individual-how the genetic legacy of your mother and father recombined to create you. It's the mixture of your father's genes and your mother's genes that gave you blue eyes, blond hair, and freckles. Mitochondrial DNA can help us to understand the history of a whole species."

"That means the origin and evolution of the species is recorded in every one of us," I said slowly. "It's in our blood and every cel in our body."

Matthew nodded. "But every origin story tel s another tale -not of beginnings but of endings."

"We're back to Darwin," I said, frowning. "Origin wasn't entirely about where different species came from. It was about natural selection and species extinction, too."

"Some would say Origin was mostly about extinction,"

Marcus agreed, rol ing up to the other side of the lab bench.

I looked at Benvenguda's bril iant hoops. "Who was she?"

"A very powerful witch," Miriam said, "who lived in Brittany in the seventh century. She was a marvel in an age that produced many marvels. Beatrice Good is one of her last-known direct descendants."

"Did Beatrice Good's family come from Salem?" I whispered, touching her folder. There had been Goods living there alongside the Bishops and Proctors.

"Beatrice's lineage includes Sarah and Dorothy Good of Salem," Matthew said, confirming my hunch. He opened Beatrice's file folder and put her mitochondrial test results next to those of Benvenguda.

"But they're different," I said. You could see it in the colors and the way they were arranged.

"Not so different," Matthew corrected me. "Beatrice's nuclear DNA has fewer markers common among witches.

This indicates that her ancestors, as the centuries passed, relied less and less on magic and witchcraft as they struggled to survive. Those changing needs began to force mutations in her DNA-mutations that pushed the magic aside." His message sounded perfectly scientific, but it was meant for me.

"Beatrice's ancestors pushed their magic aside, and that wil eventual y destroy the family?"

"It's not entirely the witches' fault. Nature is to blame, too."

Matthew's eyes were sad. "It seems that witches, like vampires, have also felt the pressures of surviving in a world that is increasingly human. Daemons, too. They exhibit less genius-which was how we used to distinguish them from the human population-and more madness."

"The humans aren't dying out?" I asked.

"Yes and no," Matthew said. "We think that the humans have-until now-proved better at adapting. Their immune systems are more responsive, and they have a stronger urge to reproduce than either vampires or witches. Once the world was divided more evenly between humans and creatures. Now humans are in the majority and creatures make up only ten percent of the world's population."

"The world was a different place when there were as many creatures as humans." Miriam sounded regretful that the genetic deck was no longer stacked in our favor. "But their sensitive immune systems are going to get humans in the end."

"How different are we-the creatures-from humans?"

"Considerably, at least on the genetic level. We appear similar, but under the surface our chromosomal makeup is distinctive." Matthew sketched a diagram on the outside of Beatrice Good's folder. "Humans have twenty-three chromosomal pairs in every cel nucleus, each arranged in long code sequences. Vampires and witches have twenty- four chromosome pairs."

"More than humans, pinot noir grapes, or pigs." Marcus winked.

"What about daemons?"

"They have the same number of chromosome pairs as humans-but they also have a single extra chromosome.

As far as we can tel , it's their extra chromosome that makes them daemonic," Matthew replied, "and prone to instability."

While I was studying his pencil sketch, a piece of hair fel into my eyes. I pushed at it impatiently. "What's in the extra chromosomes?" It was as hard for me to keep up with Matthew now as it had been managing to pass col ege biology.

"Genetic material that distinguishes us from humans,"

Matthew said, "as wel as material that regulates cel function or is what scientists cal 'junk DNA.'"

"It's not junk, though," Marcus said. "Al that genetic material has to be left over from previous selection, or it's waiting to be used in the next evolutionary change. We just don't know what its purpose is-yet."

"Wait a minute," I interjected. "Witches and daemons are born. I was born with an extra pair of chromosomes, and your friend Hamish was born with a single extra chromosome. But vampires aren't born-you're made, from human DNA. Where do you acquire an extra chromosome pair?"

"When a human is reborn a vampire, the maker first removes al the human's blood, which causes organ failure.

Before death can occur, the maker gives his or her blood to the one being reborn," replied Matthew. "As far as we can tel , the influx of a vampire's blood forces spontaneous genetic mutations in every cel of the body."

Matthew had used the term "reborn" last night, but I'd never heard the word "maker" in connection with vampires before.

"The maker's blood floods the reborn's system, carrying new genetic information with it," Miriam said. "Something similar happens with human blood transfusions. But a vampire's blood causes hundreds of modifications in the DNA."

"We started looking in the genome for evidence of such explosive change," Matthew explained. "We found it- mutations proving that al new vampires went through a spontaneous adaptation to survive when they absorbed their makers' blood. That's what prompts the development of an extra chromosome pair."

"A genetic big bang. You're like a galaxy born from a dying star. In a few moments, your genes transform you into something else-something inhuman." I looked at Matthew in wonder.

"Are you al right?" he asked. "We can take a break."

"Could I have some water?"

"I'l get it." Marcus hopped up from his stool. "There's some in the specimen fridge."

"Humans provided the first clue that acute cel ular stress from bacteria and other forms of genetic bombardment could trigger quick mutations, rather than the slower changes of natural selection." Miriam pul ed a folder out of a file drawer. Opening it, she pointed to a section of a black-and-white graph. "This man died in 1375. He survived smal pox, but the disease forced a mutation on the third chromosome as his body quickly coped with the influx of bacteria."

Marcus returned with my water. I took the cap off and drank thirstily.

"Vampire DNA is ful of similar mutations resulting from disease resistance. Those changes might be slowly leading to our extinction." Matthew looked worried. "Now we're trying to focus on what it is about vampire blood that triggers the generation of new chromosomes. The answer may lie in the mitochondria."

Miriam shook her head. "No way. The answer's in the nuclear DNA. When a body is assaulted by vampire blood, it must trigger a reaction that makes it possible for the body to capture and assimilate the changes."

"Maybe, but if so, we need to look more closely at the junk DNA, too. Everything must be there to generate new chromosomes," Marcus insisted.

While the three of them argued, I was rol ing up my sleeve. When the fabric cleared my elbow and the veins in my arm were exposed to the cool air of the laboratory, they directed their freezing attention at my skin.

"Diana," Matthew said coldly, touching his Lazarus badge, "what are you doing?"

"Do you stil have your gloves handy, Marcus?" I asked, continuing to inch my sleeve up.

Marcus grinned. "Yeah." He stood and pul ed a pair of latex gloves out of a nearby box.

"You don't have to do this." Matthew's voice caught in his throat.

"I know that. I want to." My veins looked even bluer in the lab's light.

"Good veins," Miriam said with a nod of approval, eliciting a warning purr from the tal vampire standing next to me.

"If this is going to be a problem for you, Matthew, wait outside," I said calmly.

"Before you do this, I want you to think about it," Matthew said, bending over me protectively as he had when Peter Knox had approached me at the Bodleian. "We have no way of predicting what the tests wil reveal. It's your whole life, and your family's history, al laid out in black and white.

Are you absolutely sure you want that scrutinized?"

"What do you mean, my whole life?" The intensity of his stare made me squirm.

"These tests tel us about a lot more than the color of your eyes and your hair. They'l indicate what other traits your mother and father passed down to you. Not to mention traits from al your female ancestors." We exchanged a long look.

"That's why I want you to take a sample from me," I said patiently. Confusion passed over his face. "I've wondered my whole life what the Bishop blood was doing as it pumped through my veins. Everyone who knew about my family wondered. Now we'l know."

It seemed very simple to me. My blood could tel Matthew things I didn't want to risk discovering haphazardly. I didn't want to set fire to the furniture, or fly through the trees, or think a bad thought about someone only to have that person fal deathly il two days later. Matthew might think giving blood was risky. To me it seemed safe as houses, al things considered.

"Besides, you told me witches are dying out. I'm the last Bishop. Maybe my blood wil help you figure out why."

We stared at each other, vampire and witch, while Miriam and Marcus waited patiently. Final y Matthew made a sound of exasperation. "Bring me a specimen kit," he told Marcus.

"I can do it," Marcus said defensively, snapping the wrist on his latex gloves. Miriam tried to hold him back, but Marcus kept coming at me with a box of vials and sharps.

"Marcus," Miriam warned.

Matthew grabbed the equipment from Marcus and stopped the younger vampire with a startling, deadly look.

"I'm sorry, Marcus. But if anyone is going to take Diana's blood, it's going to be me."

Holding my wrist in his cold fingers, he bent my arm up and down a few times before extending it ful y and resting my hand gently on the stainless surface. There was something undeniably creepy about having a vampire stick a needle into your vein. Matthew tied a piece of rubber tubing above my elbow.

"Make a fist," he said quietly, pul ing on his gloves and preparing the hol ow needle and the first vial.

I did as he asked, clenching my hand and watching the veins bulge. Matthew didn't bother with the usual announcement that I would feel a prick or a sting. He just leaned down without ceremony and slid the sharp metal instrument into my arm.

"Nicely done." I loosened my fist to get the blood flowing freely.

Matthew's wide mouth tightened while he changed vials.

When he was finished, he withdrew the needle and tossed it into a sealed biohazard container. Marcus col ected the vials and handed them to Miriam, who labeled them in a tiny, precise script. Matthew put a square of gauze over the stick site and held it there with strong, cold fingers. With his other hand, he picked up a rol of adhesive tape and attached it securely across the pad.

"Date of birth?" Miriam asked crisply, pen poised above the test tube.

"August thirteenth, 1976."

Miriam stared. "August thirteenth?"

"Yes. Why?"

"Just being sure," she murmured.

"In most cases we like to take a cheek swab, too."

Matthew opened a package and removed two white pieces of plastic. They were shaped like miniature paddles, the wide ends slightly rough.

Wordlessly I opened my mouth and let Matthew twirl first one swab, then the other, against the inside of my cheek.

Each swab went into a different sealed plastic tube. "Al done."

Looking around the lab, at the quiet serenity of stainless steel and blue lights, I was reminded of my alchemists, toiling away over charcoal fires in dim light with improvised equipment and broken clay crucibles. What they would have given for the chance to work in a place like this-with tools that might have helped them understand the mysteries of creation.

"Are you looking for the first vampire?" I asked, gesturing at the file drawers.

"Sometimes," Matthew said slowly. "Mostly we're tracking how food and disease affect the species, and how and when certain family lines go extinct."

"And is it real y true we're four distinct species, or do daemons, humans, vampires, and witches share a common ancestor?" I'd always wondered if Sarah's insistence that witches shared little of consequence with humans or other creatures was based on anything more than tradition and wishful thinking. In Darwin's time many thought that it was impossible for a pair of common human ancestors to have produced so many different racial types.

When some white Europeans looked at black Africans, they embraced the theory of polygenism instead, which argued that the races had descended from different, unrelated ancestors.

"Daemons, humans, vampires, and witches vary considerably at the genetic level." Matthew's eyes were piercing. He understood why I was asking, even though he refused to give me a straight answer.

"If you prove we aren't different species, but only different lineages within the same species, it wil change everything,"

I warned.

"In time we'l be able to figure out how-if-the four groups are related. We're stil a long way from that point, though." He stood. "I think that's enough science for today."

After saying good-bye to Miriam and Marcus, Matthew drove me to New Col ege. He went to change and returned to pick me up for yoga. We rode to Woodstock in near silence, both lost in our own thoughts.

At the Old Lodge, Matthew let me out as usual, unloaded the mats from the trunk, and slung them over his shoulder.

A pair of vampires brushed by. One touched me briefly, and Matthew's hand was lightning fast as he laced his fingers through mine. The contrast between us was so striking, his skin so pale and cold, and mine so alive and warm in comparison.

Matthew held on to me until we got inside. After class we drove back to Oxford, talking first about something Amira had said, then about something one of the daemons had inadvertently done or not done that seemed to perfectly capture what it was to be a daemon. Once inside the New Col ege gates, Matthew uncharacteristical y turned off the car before he let me out.

Fred looked up from his security monitors when the vampire went to the lodge's glass partition. The porter slid it open. "Yes?"

"I'd like to walk Dr. Bishop to her rooms. Is it al right if I leave the car here, and the keys, too, in case you need to shift it?"

Fred eyed the John Radcliffe tag and nodded. Matthew tossed the keys through the window.

"Matthew," I said urgently, "it's just across the way. You don't have to walk me home."

"I am, though," he said, in a tone that inhibited further discussion. Beyond the lodge's archways and out of Fred's sight, he caught my hand again. This time the shock of his cold skin was accompanied by a disturbing lick of warmth in the pit of my stomach.

At the bottom of my staircase, I faced Matthew, stil holding his hand. "Thanks for taking me to yoga-again."

"You're welcome." He tucked my impossible piece of hair back behind my ear, fingers lingering on my cheek. "Come to dinner tomorrow," he said softly. "My turn to cook. Can I pick you up here at half past seven?"

My heart leaped. Say no, I told myself sternly in spite of its sudden jump.

"I'd love to," came out instead.

The vampire pressed his cold lips first to one cheek, then the other. "Ma vaillante fille, " he whispered into my ear.

The dizzying, al uring smel of him fil ed my nose.

Upstairs, someone had tightened the doorknob as requested, and it was a struggle to turn the key in the lock.

The blinking light on the answering machine greeted me, indicating there was another message from Sarah. I crossed to the window and looked down, only to see Matthew looking up. I waved. He smiled, put his hands in his pockets, and turned back to the lodge, slipping into the night's darkness as if it belonged to him.