Marcus lasted exactly four minutes before he asked the question I had been dreading.
"Okay. Real talk." He sat on an overturned crate in the abandoned clock tower Cassian had dragged us to, still in his socks and jacket, his phone clutched in both hands like a lifeline. "Are you going to eat me?"
"No."
"You hesitated."
"I did not hesitate."
"You hesitated for like half a second, David. I know your hesitation face."
Cassian, leaning against a pillar with his arms crossed, made a sound that might have been a cough. It might also have been a laugh. On a man who had spent four hundred years watching bloodlines die, it was hard to tell.
I sat down across from Marcus and told him everything. The dream. The mirror. The blood moon. The hunger in the hallway, the stranger in the courtyard, the book, the flask. Isolde and her lily. The voice in my head. I left nothing out except the part where Cassian had held the blade, because I had not yet decided what to do with that.
When I finished, Marcus stared at me for a long time.
"So you're a vampire," he said.
"Yes."
"A special one."
"The first one, apparently."
"And you're telling me all of this was happening while I was complaining about my chemistry homework."
"I'm sorry about the chemistry."
"Don't." He pressed a hand over his mouth. A thin, cracked sound slipped out, and for a second I thought he was crying. Then I realized he was laughing, helplessly, the way people do when the alternative is screaming. "Show me. Just, show me. If I'm going to lose my mind, I want evidence."
I hesitated. Then I opened my mouth and let him see.
Marcus went completely still. He leaned forward, slowly, until his face was inches from mine, studying the points of my teeth like a scientist, and I held my breath, though I didn't need to, because I could hear his heartbeat and it was fast, rabbit-fast, and the hunger stirred under my ribs like something waking.
I clamped my mouth shut and leaned back.
"Okay," Marcus whispered. "Okay. That's real."
"Yes."
"Cool. Cool, cool, cool." He nodded rapidly. "I'm going to be sick later."
"That is reasonable," said Cassian.
"Wait. Do you sparkle in sunlight?"
"I burn," I said.
"Oh thank God. I was going to have to leave."
Cassian's head turned sharply toward Marcus's hand.
"Give me your wrist."
The mark was small. That was what made it so horrible.
Three thin black lines, no thicker than pencil strokes, curled around the inside of Marcus's left wrist like the beginnings of a bracelet. He hadn't noticed them. When Cassian pushed back the sleeve of his jacket, Marcus stared at them as though they belonged to someone else.
"That wasn't there before," he said.
"When did the Hollow first speak to you?" Cassian asked.
"It didn't. It—" Marcus stopped. His face changed. "Last night. Around two. I woke up, and my phone was on the floor, and I felt like someone had been standing next to my bed. I thought it was a nightmare."
Two a.m. The text I didn't remember sending. Don't look at the moon.
"It was warning you," Cassian said slowly, and glanced at me. "Or something was warning you through him."
"Warning me about what? What's this on my wrist?"
Cassian hesitated, and I realized I had never seen him hesitate before. "The Hollow does not kill the people it hunts. Not at first. It marks them, one line at a time. Each night it takes a little more. Their voice first. Then their sleep. Then their will." His gray eyes lifted. "On the third night, the mark closes. And what walks away from the bed is no longer a person. It is a door."
"A door," Marcus repeated faintly.
"For the Hollow to walk through."
The tower was silent, except for the slow, steady tick of Marcus's heart. Three lines. Three nights.
Just like the hunger.
"How do we stop it?" I said.
"We do not. Not unless we find the Hollow and kill it before the third night." Cassian's mouth tightened. "And I have been hunting that Hollow's kind for a very long time, David. I have never once found one that did not want to be found."
That is because they are not hunting you, said the voice in my head. They are herding.
Herding me where?
The voice went quiet. It did that when it knew something and wasn't ready to tell me.
Marcus fell asleep an hour before dawn, folded up on a pile of dusty tarps with his jacket over his head and one hand curled tight around the marked wrist, as if he could hold the lines in.
I couldn't sleep. I wasn't sure I could anymore. I sat by the broken window with my back against the cold stone, and after a while Cassian came and stood beside me, close enough that I could feel the absence of warmth coming off him.
"His name was Valerian," he said.
I didn't need to ask who.
"He had your eyes. Gold, with a thread of red. He used to say they were the only part of him that never learned to lie." Cassian's gaze stayed on the sky. "He asked me for three things, at the end. To hold the blade. To keep it. And to promise that if the blood ever woke again, I would not kill the one it chose."
My throat tightened. "Then why are you carrying a sword?"
"Because I do not know if I can keep the third promise." He said it quietly, simply, with no cruelty at all, which was worse. "I have watched the blood wake in three lifetimes. Twice, it ended in fire. If I ever believe you are becoming what he feared, David, I will have to choose between the promise and the world."
Honest, the voice murmured. At last.
"You could have lied to me," I said.
"Yes."
"Why didn't you?"
Cassian was silent for a long time. "Because he would have wanted you to hear it from me, and not from her."
Outside, the sky lightened by one shade of gray. Somewhere beneath the floor, the old clock gave a single rusted tick, and stopped.
The lily arrived at dawn.
I wasn't looking for it. Marcus was still asleep on the tarps, and I was sitting at the window watching the sky turn from black to bruised gray when I felt the cold behind me, and smelled old flowers.
A single white lily lay on the floor beside my foot.
I had left it outside my apartment. Miles away.
"Do not touch it," Cassian said sharply. He was already moving, the blade half-drawn.
"I'm not."
"You did not burn it?"
"No!"
"Then she did not need you to." Cassian crouched over the flower without touching it. "It was never an offering. It was a beacon."
From the stairwell below us, a voice floated up, soft and pleasant and utterly unbothered.
"I did warn him, David. Cassian always assumes the worst."
Isolde stood at the base of the tower's old iron staircase, in the same milk-white dress, with the first thin line of sunrise just starting to turn the windows gold. She stopped at the bottom step, the way she'd stopped at my door. The tower, apparently, was not Cassian's home. It had no invitation to give her.
It also had no roof left, I noticed. A beam of dawn was already sliding down the far wall, inching toward her.
"You have until the sun reaches the second window," Cassian said coldly. "Then you leave."
"I only need a moment." She never took her eyes off me. "You found your friend's mark, I see. How awful. Three lines already."
Marcus had woken, and was sitting up, pale and wide-eyed. "Why does she know about that?"
"Because I can cure it," Isolde said gently.
Silence.
"No," Cassian said.
"I have not even said how."
"You do not need to. I know how."
"Then you also know," Isolde said, still looking only at me, "that there is exactly one cure for a Hollow's mark. One thing in this world that burns it clean. And the only person alive who can give it to him is standing in this room."
The sun reached the first window. A beam fell across the floor.
No, said the voice, and now it was almost pleading. Do not ask her what it is.
"What is it?" I asked.
"Your blood, David." Isolde smiled, small and sad. "A single drop, freely given, would burn the Hollow out of him. Cleanly. Painlessly. By dawn tomorrow he would be perfectly well."
My heart, the slow one, gave a hard, sudden thump.
"That's all?"
"Almost all."
"Almost," Cassian said, and I heard the bitterness in it, "because a Progenitor's blood does not simply heal. It changes."
I looked at him. "Changes him how?"
"Into one of us."
Marcus made a small, strangled noise.
"Bound to you," Cassian went on, grim. "Your will over his, for as long as you both exist. That is what the First Blood does. That is what it did to every servant it ever made, and why the last Progenitor refused to make any, and why I—" He stopped himself.
"Why you what?" I said.
He didn't answer.
"A fine choice," said Isolde. "Let your friend become a door for the Hollow. Or make him a vampire, and a servant, and yours. Which, I suspect, is exactly what the Court has been trying to tell you. The blood is not a gift, David. It is a leash. You only get to choose who holds the other end."
The second window turned gold.
"Time," Cassian said.
"Of course." Isolde stepped backward, one hand lifted in farewell. "You know where I am. Burn the lily when you are ready."
Then she was gone, and the beam of sunlight crawled forward across the empty stairwell.
I turned around slowly, because I could hear something behind me, the soft, wrong sound of a heartbeat that had gone slow.
Too slow.
Marcus sat very still on the tarp, with his hands in his lap and his head tilted at an odd angle, as if listening to something far away. The black lines had crept past his wrist and were climbing his forearm like ink spreading through water.
"Marcus?"
He lifted his head.
His eyes were white. Not pale. White, like a blank page, with no iris and no pupil, and a long, thin slit of a smile spreading across his face that did not belong there.
"Hello, little king," said the Hollow, in Marcus's voice. "He is a lovely door, isn't he?"
I lunged for him, but Cassian caught me by the collar and hauled me back. "Wait! It is inside him. If you strike it, you strike him!"
"Then how do we—"
"Choose quickly," the Hollow purred, tilting Marcus's head to the other side. "He has only two more nights. And I am so very patient."
The slit of a smile widened.
"And David? When you do choose, remember who it was that really called you."
Marcus slumped forward, and the white faded from his eyes. He gasped, blinked, and grabbed my arm with a shaking hand.
"David," he whispered. "I can still hear it."
"Hear what?"
"It's still talking." His face had gone gray. "And it just told me the real reason Cassian killed the last one."