Chapter 1The Test Subject

The rain, laced with residual oath-magic, burned against Cinder's scars.

She hauled the stranger through the twisting alleyways of the floating island, his blood slicking her hands, his feet dragging uselessly across the wet stone. Behind them, the Sunstone agents chanted in unison, their oath-light tracking spells casting long blue shadows through the night.

"Left," the stranger gasped. "Smithy. Abandoned."

Cinder didn't ask how he knew. She just grabbed his collar and yanked him around the corner, her boots skidding on the rain-slicked cobbles. The smithy's door hung crooked on its hinges, the interior dark and cold as a tomb. She shouldered him inside, kicked the door shut, and pressed her back against the wall.

The oath-light pulsed outside, searching.

She pressed her palm flat against her chest, where the worst of her Vowbreak scars twisted like silver roots beneath her skin. The magic there was dead—had been dead for three years—but dead magic left echoes. She focused, remembering the dissonance, the fracture, the moment her oath shattered and took everything with it.

The scars warmed. Then they *hummed*.

A low, discordant vibration rippled outward, warping the air around the smithy. The oath-light outside flickered, stuttered, and went dark. Voices cursed in confusion. Footsteps scattered, searching elsewhere.

Cinder let her hand fall. The hum faded.

She stood there a moment, breathing hard, the stranger's blood cooling on her fingers. Then she turned to him.

He'd collapsed against a rusted anvil, one hand pressed to his gut, where a blade had punched through leather and flesh. His face was the color of old ash. He wasn't going to make it.

"Stay with me," she said, kneeling beside him. "Tell me what you stole."

His lips cracked open. "Data cylinder. Pocket. Left."

She found it—a slim silver tube, still warm from his body. She rolled it between her fingers. "What's on it?"

"The truth." He coughed, and blood bubbled at the corner of his mouth. "About the project. The *child*."

Cinder's throat locked. She didn't ask which child. She knew.

"I was a researcher," he said, each word costing him. "Quiet Earth lab. Deep beneath the Spire. They were experimenting with oath manipulation. Trying to break oaths without killing the swearer."

"That's not possible."

"It is now." His hand found hers and squeezed once, hard. "They needed a test subject. Someone bound by a deep, personal oath. Someone whose breaking would create maximum... resonance."

Cinder's scars throbbed. She remembered the oath she'd sworn to her commander—*I will protect the innocent, no matter the cost*—and the moment she broke it to save a child who died anyway.

"The child," she whispered. "She was part of the experiment."

"She *was* the experiment." His eyes locked onto hers, fierce even through the pain. "She was a clone. A vessel designed to trigger a specific oath-breaking cascade. They made her to test the ritual. You were never meant to save her, Cinder."

The world tilted.

"You were the test."

She heard the words, but they didn't land. They hovered in the air, wrong-shaped, impossible to hold. A clone. A *test*. The child she'd betrayed her kingdom for, her honor for, her *life* for—she was never real. She was a tool. A piece of lab equipment designed to break Cinder's oath and measure the fallout.

"What do you mean, 'measure the fallout'?"

But the stranger's hand had gone slack. His eyes stared at the ceiling, unseeing.

He was gone.

Cinder sat there, the data cylinder cold in her palm, the stranger's blood drying on her skin. The silence of the smithy pressed in around her. She waited for the grief to come—for the rage, the numbness, the familiar spiral of self-loathing.

Nothing came.

She felt a lingering weight in her chest, like an oath she couldn't remember breaking. A quiet wrongness that had been there so long she'd stopped noticing it. But now, with the stranger's words echoing in her skull, it pulsed. Alive. *Curious*.

She pushed the feeling aside and activated the data cylinder.

A hologram flickered to life, casting pale blue light across the smithy's rusted walls. A face formed—familiar, sharp, wearing that half-smile she remembered too well.

Thorne.

He'd been in prison for six months. How did a hologram from a stolen data cylinder have his face?

"I knew you'd find this, Cinder," he said, his voice tinny through the projection. "I knew you'd find *him*."

She stared at the image. Thorne looked older than she remembered, the lines around his eyes deeper, but his gaze held the same unbearable certainty. The same conviction that he was right, and everyone else was wrong.

"You want to know about the child. About the experiment." He tilted his head. "But you're asking the wrong question. You're asking *why*. The real question is *who*."

The projection flickered.

"Who do you think funded the lab, Cinder? Who do you think designed the ritual? Who do you think chose the test subject?"

She thought of the child's face. Pale. Hollow. Eyes that had never learned to smile.

"Someone very close to you."

The hologram flickered again, and a proximity alarm blared from the cylinder's casing. Footsteps outside. The Sunstone agents had circled back.

"Ah," Thorne said, smiling. "I'm out of time. But before you go running again—remember this: you think you're free of oaths, Cinder? You're bound tighter than ever. You just don't know it yet."

The hologram died.

Cinder shoved the cylinder into her pocket, grabbed the stranger's collar one last time—to close his eyes, to offer some dignity—and then she was moving, vaulting through a shattered window into the rain.

The alarm wailed behind her.

The agents' voices called out, closing in.

And in her chest, that weight pulsed again, like a second heartbeat she'd never noticed before.

*Bound tighter than ever.*

She didn't know what it meant.

But she was going to find out.