Fragments of sound. Motion. A voice. “Elisabeth.” The voice belonged to Nathaniel, tight with barely controlled emotion. “Elisabeth, can you hear me?”

His face hovered over her, a pale, blurry smear against the dark. Soot marked his cheek, and green embers swirled through the night behind him. He was cradling her with one arm, the other gripping her hand, squeezing it desperately. Her breath caught when she saw her fingers, shriveled and leached of color. But as she watched, the Malefict’s touch receded. Sensation returned to her hand in a rush of pins and needles.

Nathaniel helped her up when she struggled to stand. Around them, devastation. Emerald flames licked over the battlements and danced along the empty uniforms scattered across the rampart. A lone cannon boomed, and a shriek reverberated through her ears—the Malefict. Nearby, the Director was barking orders, trying to rally the remaining wardens.

“I’m all right,” Elisabeth said, adjusting her grip on Demonslayer. “I’m ready.”

Nathaniel had a peculiar look on his face. He glanced meaningfully at Silas, then took a step backward. A protest rose to her lips even before he spoke. “I’m going to draw it away—”

“No.”

“I have to. I’m the only person who isn’t affected by its magic.”

“Wait,” she said. “You shouldn’t. The voice—you might not be able to resist it.”

“Don’t worry. I have an idea. There isn’t time to explain, but . . .” He was already turning, a fiery whip unraveling between his hands, its light transforming him into a tall, slim silhouette. The last thing she saw was a hint of a smile. “Trust me.”

Ahead of him, the Malefict finished raking its claws through a tower and turned, chunks of masonry tumbling down its shoulders. Though it resembled the moss spirit they had seen in the Blackwald, the bark that made up its hide was darkened and decayed, split in places to reveal an inner green glow. Nathaniel looked impossibly small walking toward it, his whip a mere thread of light.

Elisabeth wasn’t going to stand by and watch. She shoved Demonslayer through her belt and dashed toward the nearest cannon, its previous operator nothing but a uniform and a pile of dust. Sweeping the remains aside, she climbed onto the gunner’s seat.

The device was a far cry from the medieval-style cannons she had read about in books. Like the rest of the Great Library’s mechanisms, it was a complex instrument riddled with gears and pistons. She seized a wheel and experimentally wrenched it to the left, its metallic chill biting into her fingers. Machinery rumbled to life, shaking the seat so violently that only her grip on the wheel prevented her from being flung off. With a protesting groan, the cannon’s barrel swung several feet to the left. Now, up. She heaved on an adjacent wheel, and the barrel rose. All that remained was a lever beside her hip. That had to be what fired the cannon.

Nathaniel’s whip spun out, readying to strike. But he didn’t follow through. He stood still, gazing upward as the Malefict stooped over him. Her heart skipped a beat, remembering the transfixed expression on his face in the vault. Move, she urged. Fight.

In the silence, the forest exhaled a breath. Wind swirled over the rampart, fetid with decay, as though issued from the mouth of a corpse. Boughs bent. Branches creaked. And a voice whispered, “Thorn . . .”

“Don’t listen to it!” Elisabeth screamed. Her pulse throbbed against the collar of her coat as she rammed the lever down.

A rattling sound came from within, like chain links winching upward. The barrel shuddered, its mouth glowing red-hot. Then the cannon bucked in recoil, rattling her teeth and numbing her arm to the elbow. Somehow, she didn’t let go.

There came a thin, high whistling, and then a thud. She stood, clutching the wheel for balance. Green light roiled around a metal ball embedded in the Malefict’s chest. Elisabeth knew the cannonball must be huge, but against the monster’s colossal frame, it appeared no larger than a marble.

The Malefict had barely reacted. She began to wonder whether this had been a foolish idea. Then, the cannonball exploded.

The Malefict shrieked as splinters of its barklike skin went flying. A white cloud puffed around the crater left behind—salt. The cannonball was an iron-coated salt round.

Far below, Nathaniel shook his head as though trying to clear it of cobwebs. His shoulders tensed, and he swept his whip through the air, the flame sizzling as it wrapped around one of the Malefict’s wrists. Jerking the monster off balance, he raised his other hand, which let loose a volcanic blast of green fire. Thrown back, the Malefict caught itself by clamping its claws down on a battlement. As the smoldering embers fell, it regarded Nathaniel at eye level, near enough to reach out and seize him.

“I know you,” it whispered instead. “Son of House Thorn, master of death.”

“No,” Nathaniel croaked, stepping back.

“Why do you hide your nature? Deny the call in your blood?”

Terror lanced through Elisabeth’s chest. “Nathaniel!” she shouted. He didn’t react, didn’t even seem to hear her.

“I see,” the Malefict said. “You wish to spare the girl you love. But you know the truth of magic. The greatest power springs only from suffering.” It drew closer to him, its spindle-toothed mouth seeping smoke. “Join me,” it whispered. “Master of death, become the darkness that haunts you. Kill the girl.”

Nathaniel’s arm drifted to his side, the whip fizzling out. Slowly, he turned. Elisabeth didn’t recognize the expression on his face. His coat was torn, and his eyes were rimmed in red.

Mouth dry, she spun the wheels, angling the cannon into a new position. She slammed the lever down again. As Nathaniel strode toward her, flames rippled over his shoulders and down his arms like the blossoming of some strange, translucent flower.

The cannon coughed. Stone sprayed several yards in front of the Malefict, a miss. She couldn’t aim directly at its head without risking hitting Nathaniel.

Green flashes lit the rampart. The sky above them roiled, a violent, churning mass of storm clouds. Surrounded by a corona of fire, he looked barely human, untouchable.

Elisabeth’s hands trembled on the controls. “Nathaniel, stop!”

He wasn’t listening. As he continued to advance, lightning streaked through the sky, arcing between the peaks of the mountains. The earth rumbled as snow cascaded down a nearby peak, the avalanche boiling over the trees that dotted the slope with enough force to level a village. Elisabeth had never seen such raw destruction. Worse, Nathaniel didn’t appear to even be aware that he was doing it.

A terrible thought struck her. She could adjust the cannon’s aim. The cannonballs were made of iron; he wouldn’t be able to stop one if she fired it at him. If that was what it took—if that was the only way to end this, to keep him from becoming another Baltasar—

A cool touch stayed her hand. “Wait,” Silas said. His hair had come free, flowing in the wind. She didn’t understand how he could look so calm.

Nathaniel was almost upon them. Sorcery glazed his eyes. Flames rolled off his body like a cloak. In a moment, it would be too late to stop him.

“Elisabeth.” His voice echoed unrecognizably with power. He held out his hand. The fire billowed back, away from his sleeve, so she could take it.