I hit the lock button, my heart hammering against my ribs so hard it felt ready to crack them open. The speakerphone auto-connected before I could touch the screen, filling the quiet cabin of the SUV with my own calm, measured voice.

“You’re looking at what you were meant to replace, Clara,” my voice said through the static of the dashboard speakers. “Drive through her, or Eleanor wins.”

I stared through the glass. The woman on the snow-drifted asphalt didn’t blink. Behind the open flap of her cheek, tiny gears spun in frantic, silent precise loops, catching the bright halogen glow of the headlights. Leo let out a sharp, terrified squeal from the backseat, his small hands clutching the harness of his car seat.

My foot wavered over the gas pedal. “Who are you?” I screamed at the dashboard. “Who is talking to me?!”

“I am the first Clara,” the voice on the phone replied, smooth and entirely unbothered. “The one who didn’t survive the crash ten years ago. Now press the pedal before your father finishes Mark.”

A heavy metallic thud rattled the roof of the SUV.

The frame groaned under a sudden, crushing weight. Snow slid off the back windshield in a heavy sheet as two brass-tipped fingers pierced through the thin sheet metal above my head, peeling the steel open like paper. A gust of freezing, ash-scented air poured into the car.

I slammed my foot to the floor.

The tires spun violently, burning rubber against ice before the treads caught, launching the heavy vehicle forward. The double standing in the road didn’t move to dodge; she simply braced herself, her open-jawed metallic face illuminated in the final second before impact. The heavy front bumper slammed into her midsection with a sickening crunch of shattered glass and snapping brass. The SUV jolted violently as we ran over her, the undercarriage grinding her clockwork body into the asphalt.

Above me, the hands tearing through the roof lost their grip. My father’s body slid off the back of the accelerating vehicle, tumbling into the dark expanse of snow behind us.

I didn’t stop. I pressed the accelerator until the speedometer needle pushed past seventy, winding down the treacherous mountain pass in pitch darkness. The phone call had disconnected, leaving only the sound of Leo’s frantic breathing and the whistle of wind tearing through the hole in the roof.

On the passenger seat, the bronze lockbox sat heavy and silent.

I reached out with a trembling hand, pulling it onto my lap as I steered with one hand through the blinding blizzard. The lock on the front wasn’t a standard keyhole. It was an array of five concentric brass rings stamped with Roman numerals.

Near the base of the mountain, the winding road gave way to the derelict perimeter fence of the abandoned industrial district. I veered off the road, crashing through a rusted chain-link gate and tucking the SUV into the shadow of a decaying brick warehouse. I killed the headlights and killed the engine.

Silence dropped like a heavy curtain, broken only by the ticking of the cooling engine and the sound of my own ragged breaths.

“Mommy?” Leo whimpered from the back, his small voice trembling. “Is the fire coming?”

“No, baby. We’re safe,” I lied, unbuckling my seatbelt and reaching back to pull him into my arms. I held him tight against my chest, feeling his warm, beating heart—the only thing in this nightmare that felt undeniably real.

I set the lockbox on the dashboard beneath the dome light.

Check his left hand, Mark had said. Look at his hand.

I raised my own left hand into the soft yellow light of the interior lamp. My skin was smooth, pale, and unbroken. But as I pressed my thumb hard into the flesh of my inner wrist, searching for a pulse, I felt something hard just beneath the surface. A small, rigid metal cylinder embedded right alongside the artery.

My stomach churned with dark nausea. I pinched the skin tighter, and a faint, rhythmic pulse of blue light glowed through my skin, matching the rhythm of my heart.

I wasn’t the human child who survived. I was the lock.

Before I could process the terror rising in my throat, a loud, heavy knock echoed off the driver’s side window.

I flinched, clutching Leo so tightly he let out a gasp.

Standing in the shadows outside the window was Mark. His face was covered in soot, his jacket torn, and blood dripped from a deep gash along his temple. But he was breathing. He tapped on the glass again, holding up a small, blood-stained silver key—the key my father had claimed Eleanor took.

I let out a breath I didn’t know I was holding and unlocked the door. Mark pulled it open, leaning heavily against the frame, his chest heaving.

“You made it,” I breathed, tears pricking my eyes. “How did you escape him?”

“He fell into the floorboards when the second floor collapsed,” Mark wheezed, climbing into the driver’s seat and pulling the door shut behind him. He reached out, his hand shaking as he touched my cheek. “Are you alright? Is Leo okay?”

“We’re okay,” I whispered, holding out the lockbox. “Mark… I have the embedded tracker. I’m one of them. My wrist—”

“I know,” Mark said quietly, his eyes darkening with a cold, uncharacteristic stillness. He reached over and picked up the lockbox from the dashboard. “Your father built you well, Clara.”

I froze. The ambient heat in the car seemed to plummet instantly.

Mark didn’t look at my face. Instead, he reached up to his own neck, slid his thumb beneath his collar, and pressed down hard on his collarbone.

A tiny, mechanical latch clicked beneath his skin.

Mark turned his head slowly toward me. The right half of his neck split open cleanly along a seamless line, exposing a cluster of silent, gleaming steel pistons moving rhythmically in time with his speech.

“Eleanor didn’t betray your family, Clara,” Mark said, his voice dropping an octave into a flat, synthetic monotone. “She was trying to destroy us before we activated the rest of the town.”

Outside the fogged windows of the SUV, dozens of pairs of bright blue lights flickered to life in the pitch-black shadows of the surrounding warehouse.