None of that made any sense to her, but she took her bag and walked away from the car into the chill Paris night. Her breath steamed. Around her, the woods smelled of wet humus, as if it had just rained on the old, rotting leaves. She found a path and walked along it, hearing the car start up behind her and drive off. Oddly, the darkness became less pervasive as she went deeper in, details weirdly visible as if it was a painted landscape bathed in ultraviolet light.

Her phone vibrated. She stopped. She had a message from Kwasi: Urgent NSF still wants hear from U. Paris? Maybe WHO. Not us. Will inquire. Kwasi

She stopped. Vincent had lied. Kwasi hadn’t been contacted at all, knew nothing about this, which lent some credence to Decebal’s interpretation of events. And her eyes, the way she could see in the darkness, like a superhero with magical powers. She could even see the tree roots ahead of her. Was Harry even here? She had to know.

The path led to a structure shaped like a chess piece rook. Someone in a long coat stood beside it, still, seemingly unaffected by the cold. Nearing him, she had the same frisson as with the driver, an inherent repulsion. He said nothing, but pointed to a metal door in the side of the tower. Both it and the tower had been sprayed extensively with graffiti.

Inside, an old metal staircase corkscrewed down into more dimness. The space smelled of ancient wet stone and rot, and another stink beneath that, which she identified as human bowels: a sewer.

She was halfway down when Harry Gordon stepped into view below. He wore slacks, and an open windbreaker over his belly. “Hey, Rooksie,” he said. “You know, Vinnie wasn’t convinced you were coming, but I knew.” He opened his arms and embraced her in a bearlike hug. He smelled vaguely unpleasant, like a cheese that had gone off.

For an instant she experienced the same repulsion, and reacted by stepping away from him. He gave her a strange look, as if he wanted to see deep inside her, and the repulsion was replaced by an inexplicable desire to kiss him. He seemed to be fully aware of her emotional sea change, and broke into a lewd grin, which revealed a mouthful of needle-like teeth.

Ruksana gasped. “Harry.”

“Oh.” He put a hand over his mouth, pretending embarrassment. “It’s my Celtic roots come to the fore.” He dropped the hand and laughed. “I really haven’t worked this all out yet you know?” He made a self-deprecating smile. “You wouldn’t have realized it, but I was planning to kill myself when I got home. I mean, Linn’s dead, they were gonna split me open like a lobster to clean out my arteries, and NOAA was ready to retire me. So, what the fuck? And I got home and this happened, almost immediately. It was weird, you know? I knew and I didn’t know what was going on, all at the same time. Like the old me was still in complete denial about this. Vincent figured it out, though. Hell, he called me, told me to get over here before NSF nabbed me. Our old pal, Kwasi, had them all scrambling.”

He inspected her teeth. “I see you don’t have any obvious fangs. Then again, what I don’t know about Romanian vampires would be everything. I do like the hair, though. That’s very sexy on you.” He squeezed her arm. “Come on, let’s go see Vinnie. He’s back in the Crawl with a few snacks. Saved you one. He’s still a prick, though.”

As he led her through the old stone tunnel, Harry played tour guide. “If you went back the other way, you’d find the ossuaries and the tourists. That’s the 1786 part of the catacombs, when Paris decided to stuff the diseased corpses down underground in these old Roman quarry tunnels. You watch the limestone walls closely, you’ll see some fossils in them — should appeal to the geologist in you. Go down this way farther, you’ll hit water. You’d think the Phantom of the Opera was going to sail by.”

The sharp tang of the place lay on the back of her tongue like a paste of chalky salt. Ahead somewhere, a man yelled, but stopped almost immediately. She became aware of a soft guttural sound nearby, like a muted growling.

Harry gave her an approving glance. “Getting hungry, are you?”

Startled, she realized that the noise had been coming from her. Covering her shock, she asked, “Is John here, too?”

His alluring gaze faltered. “No,” he said. “John didn’t make it. Best we can figure, he turned in the middle of the flight home from Rio, while he was asleep. Woke up remade and attacked the passenger next to him on instinct, took a major bite out of the guy’s arm before other passengers and crew wrestled him down. Some military ex-commando was on board, and pretty much dislocated one of his arms. They strapped him into an isolated seat, but then the sun came up, and he couldn’t move. Wasn’t like me. Broiled him where he sat. Poor bastard never had time to adjust to the change.” He shook his head. “But Deb’s here with us, and Childs — he’s off down the tunnels somewhere, hunting cataphiles.”

“Cataphiles?”

“Yeah, teenagers, twenty-somethings from Britain and Germany, places like that, they break in and sneak down here. There are about a million places to do that, too. Cataphiles go exploring, spend days down here without surfacing. On top of them, you got all kinds of squatters. Childs likes to work solo, enjoys the adventure of the hunt and culling the herd. I’m not sure what kind he is, but he shares some of my talents. Look him in the eye, he’ll give you an orgasm.”

They arrived at an opening in the wall. Kerosene camping lanterns turned low stood on the floor to either side.

“Go on in,” said Harry. “You’re expected.” He grinned at her, and again she felt that allurement. It reminded her of her grandfather’s stories of faeries and how they could beguile those they desired. The changes weren’t imagined. They were real. It was all real. Those folktales had been handed down from a time when such things were possible; and now, somehow, they were possible again.

She stepped into The Crawl. It seemed to be a series of interconnected chambers. The first one was strewn with debris: wrappers from power bars, crushed soda cans, broken glass bottles. More graffiti and bright murals decorated the walls. A skinny man who looked like a drug addict lay on a filthy sleeping bag in one corner. He looked up at her. His eyes were bloodshot. He smiled just to show her his fangs.

“Vincent!” called Harry. He was answered by loud animal sounds, like from a pack feeding hyenas. To Ruksana, he said, “Let’s go in here,” and led her through another doorway.

The corridor was narrow and low. It emptied into a large room with a rough uneven floor and sides that had been carved out to form makeshift benches.

“Look at this,” he said. He stood beside another carving. Someone had taken the time to carve a miniature castle out of the rock. There were crenelated towers on both sides of the main entrance, which needed only a drawbridge. The central keep stood shoulder high beside Harry. “Amazing, isn’t it? Somebody had a lot of time on their hands.”

In the center of the room hung a wide circular chandelier that seemed to have come from such a medieval castle. Four thick candles burned on its rim. Despite the size of the room the ceiling was so low that even she would have had to duck to get under the chandelier. A sense of claustrophobia had already taken root in her and now swelled by the moment. She thought of the moon outside, thought of its light. She grew increasingly terrified that without that light she was helpless.

Behind her, someone shuffled into the narrow corridor, and she turned around.

A tall slender figure emerged. He was dressed all in black: slacks and turtleneck. The sweater shone wetly from the dark stream that had run down from his mouth over his chin. In the dim light, it looked for a moment as if the whole lower part of his jaw was gone, instead of merely hidden behind a pennant of blood. She gasped as he stepped into the candlelight.

Vincent was more obviously altered than Harry. His eyes were dark and sunken, like holes in his face. His skin had gone gray. The handsome libertine had transformed into a ghoul. “I’m so glad you came,” he said. His teeth were all sharp, too, but spade-like, not the needles between Harry’s lips. He sniffed the air as if trying to get the scent of her perfume. “I can smell the change in you. I was worried you hadn’t come over. McCabe didn’t — did he tell you? We called him. Martin knew what had happened to John and was already turning himself in to some CDC office in the U.S. But he hadn’t changed, not one bit. Don’t understand any of that, do we, Harry?”

He came closer. Behind him, Deb Arliss came into the room. She looked surprisingly like herself, although with two fangs glinting, and blood on her lips and spattered down the front of her coat. Behind her two more, who hadn’t been members of the team. They looked plump, well fed, their faces flushed. They held between them a naked teenager. He was bleeding from multiple wounds but was still alive. Vincent glanced around at them and then back at her. “That’s right, the word’s gotten out that we’re down here in the hypogea. I know you were thinking it has to be that biofilm that got on us — maybe so, but these people had already turned before I came home. Ahead of all of us. How is that possible, can you imagine? Did some earlier ice sail into the Gulf Stream and melt, do you think? Or maybe a flock of procellariids scooped some up and shat it out over Notre Dame and New York.”

He chuckled. “These fellows were so confused, directionless. Trying to hide what they were, and starving for it. Whereas I, the moment I changed, I knew I needed to be underground. I experienced the most terrible cramps, I can tell you. I thought it was airline food — which might in some sense be true. I’m afraid I’d feasted on a stewardess before I knew what I was doing. I had invited her to spend the night with the least honorable of intentions, but, well, I ate her instead. It turns out I’m anthropophagous, so I’m not like the others here. Except perhaps for you since we don’t know what you are.” He paused for a moment as if listening for something no one else could hear. Then he said, “Harry, here, can go outside in the daylight. Doesn’t bother him in the slightest. He’s a — what did you call it?”