“I think you’ve had too much laudanum,” she said. She pushed open the unresisting door and drew him inside.

The stink of aetherial combustion almost choked her. As she looked around, the back of her neck prickled. The curtains were drawn, letting in only enough light for her to make out that the room appeared empty. A few small objects that she couldn’t identify lay scattered across the center of the room, as though children had once lived there and left a few of their toys behind. For the first time in weeks, she felt the imaginary presence of the house’s ghosts, of Nathaniel’s dead. Moving carefully, she lowered him to the floor and crossed the room to yank open the curtains.

Dust swirled amid the sunlight that flooded in. Looking down, she jumped aside. An elaborate pentagram was carved into the floorboards beneath her feet, the grooves burnt black and caked with grime. Stains darkened the wood within and around it—bloodstains, some of them so large she wondered whether they marked places where people had died. The objects she had glimpsed turned out to be half-melted candles, anchored in pools of their own wax at each of the pentagram’s five points. Two other items waited on the floor beside the circle. A matchbox and a dagger, the metal dulled by a patina of dust.

She remembered what Silas had said to her all those weeks ago. You would not wish to see. This was where he had been brought into the mortal realm, not once in the distant past, but time and time again.

Nathaniel fumbled with the matchbox, his fingers trembling too violently to withdraw a match. Elisabeth tucked Demonslayer under her arm and took it from him. “I want to help,” she said. “How is this done?”

He looked up at her, so pale, the steeply angled light shining translucently through the thin fabric of his nightshirt, revealing the outline of his body beneath. He looked like a ghost himself. “Are you certain?”

This was worse than using the scrying mirror. Worse even than stealing from the Royal Library. On the first day of her apprenticeship, Elisabeth had vowed to protect the kingdom from demonic influences. If she participated in a summoning, and a rumor somehow got out, even a whisper of speculation, every Great Library would be closed to her. No warden would speak to her. She would become an outcast from the only world in which she had ever belonged.

But her oaths meant nothing if they asked her to forsake people she cared about in their greatest moment of need. If that was what being a warden required of her, then she wasn’t meant to become one. She would have to decide for herself what was right and what was wrong.

Though she didn’t speak, Nathaniel saw the answer written on her face. His hand curled into a fist against the floor. She thought that he might attempt to dissuade her, but then he said, “Light them in order, counterclockwise. Make sure you stay outside the circle. Don’t cross the lines. That’s important.”

Elisabeth clumsily struck a match with her bandaged hand and moved around the pentagram. As each candle flared to life, it seemed to mark the immolation of something past and the beginning of something new. So many of her memories were characterized by flame. The gleam of candlelight on Demonslayer’s garnets. Warden Finch, the ruddy glow of a torch playing across his face, asking her if she was consorting with demons. The Book of Eyes reduced to ashes on the wind.

As she shook out the final match, she looked up to find the dagger in Nathaniel’s hand. Before she could react, he drew it along his bared wrist, beside the scar that twisted up his forearm. Only a shallow cut, but the sight of blood beading on his skin still made her heart skip with a fluttering anxiety she had never felt before on anyone else’s behalf. When he was finished, the dagger fell from his weakened grip.

“Stand back,” he said. He pressed his wrist to the edge of the circle, leaving a red smear on the floorboards. When he spoke again, his voice echoed with ancient power. “By the blood of House Thorn, I summon you, Silariathas.”

Silariathas. Silas’s true name. It did not slither from her mind like the other Enochian words she had heard Nathaniel speak, but stuck fast, smoldering, as if branded by fire onto the surface of her thoughts.

Outside, the sun sank behind the rooftops, plunging the room into shadow. A breeze disturbed the stagnant air, snuffing out all five of the candles simultaneously. The curtain rings chimed as the drapes stirred. And a figure appeared at the center of the pentagram.

He wore nothing but a white cloth draped loosely around his waist. In his nakedness he appeared not just slender, as she had thought of him before, but thin, almost gaunt. Shadows traced his ribs, the bones of his wrist, the sharp edges of his shoulder blades, a form elegant in its spareness, as if everything unnecessary had been pared away. His unbound hair hung in a straight and silvery cascade that fell past his shoulders, hiding his downcast face. Where the sword had entered him, his chest was smooth. He looked different like this—more beautiful, more frightening. Less human than ever before.

He lifted his head and smiled. “Hello, Nathaniel.”

TWENTY-EIGHT

FOR A MOMENT, nothing happened. Gazing up at Silas from the floor, Nathaniel wore the expression of a man about to plunge into a battle that he knew he could win, but only at a terrible cost. Elisabeth didn’t understand. She hadn’t expected a joyful reunion to take place inside a blood-soaked pentagram, but this . . . it felt wrong. There was something so strange about Silas’s smile.

“Silas,” she said, stepping forward. “Are you all right?”

“Don’t.” Nathaniel’s rough, urgent command struck her like a slap. His hand caught her wrist. “Don’t touch the circle.”

She could have easily shaken off Nathaniel’s hold. Instead, it was Silas’s look that stopped her in her tracks. His pupils were so dilated that his irises appeared black, circled by a thin yellow edge, like the sun during a full eclipse. His eyes held no trace of his usual self, no sign that he even recognized her.

“He can’t cross the lines,” Nathaniel said, “but the instant you touch them, he will claim your life. He’ll kill you.”

That made no sense. Yesterday morning, Silas had brought her breakfast. He had helped her into her ball gown and clipped on her earrings. But Nathaniel wouldn’t say something like that unless he meant it. “What’s wrong with him?” she whispered.

Briefly, Nathaniel squeezed his eyes shut. Sweat glistened at his temples, pasting down a few curls of his hair. “He’s hungry,” he said after a long pause. “Usually, highborn demons are summoned directly after their previous master has died. When they’re sated, they’re easier to bargain with. But it’s been six years since . . .”

Since the death of Alistair Thorn, Elisabeth thought. Since Silas’s last payment.

“Silas isn’t human,” Nathaniel went on. “When he’s like this, the time we’ve spent with him, the understandings we’ve reached—none of that matters any longer. The hunger is too great.”

And Silas wasn’t just hungry. He was starving. Slowly, he turned his unnerving gaze back to Nathaniel. If he cared that they were talking about him, or even heard them, he gave no sign.

“Silariathas,” Nathaniel said, with a calmness Elisabeth couldn’t fathom, though perhaps it was the laudanum, or the blood loss, or the simple fact that he had faced this version of Silas before. “I have summoned you to renew our bargain. I offer you twenty years of my life in exchange for your service.”