The rhythmic beep of the heart monitor in the glass vault echoed up the cold concrete stairs like a ticking bomb.

Clara froze on the step, her hand still resting against Julian’s icy, sweat-slicked cheek. Beneath her palm, his breathing was growing agonizingly shallow, each ragged intake of air sounding like shattered glass in his chest. She looked down at him in the blinding beam of the spotlight, then back down into the subterranean laboratory at her sister.

«You’re late, Clara,» Eleanor said, her voice smooth and devoid of panic through the hidden intercom system. She casually pulled on the left surgical glove, the latex snapping crisply against her wrist. «Though I suppose dodging Arthur’s theatrical suicide took up a bit of your time.»

«He threw himself off the roof to save us!» Clara shouted, her voice raspy and choked with smoke. She tried to lift Julian, but her trembling muscles betrayed her, her knees buckling against the concrete. «He gave his life to wipe the network!»

Eleanor let out a sharp, pitiless laugh, stepping around the metallic desk toward the gurney. «Arthur didn’t wipe anything. He was a sentimental fool to the very end. He thought he was purging the biometric ledger, but he was actually executing the transfer protocol. Why do you think your mother’s helicopter took off on autopilot?»

Clara’s heart hammered against her ribs. «What are you talking about?»

«Evelyn isn’t being arrested by federal servers, sister. She’s being delivered,» Eleanor replied softly, tapping a series of commands into a glowing glass console beside the gurney. «To the primary facility in Geneva. Arthur didn’t destroy the data—he consolidated it into a single vessel.»

Eleanor gestured toward the masked man on the gurney, whose chest rose and fell in unnatural, mechanical precision.

«And who is that?» Clara demanded, her grip tightening on Julian’s jacket as a cold dreadful realization began to form in the pit of her stomach.

Eleanor turned her head, her dark eyes glittering under the harsh white spotlight. «That’s the real tragedy of this family, Clara. You’ve spent five years mourning a dead father and hunting a rogue husband, never once asking yourself why Julian’s blood type matched the registry in the shipping yard raid.»

Before Clara could process the words, the monitor on the desk chimed sharply. A red warning light began flashing across the glass walls of the vault.

CRITICAL BIOMETRIC MISMATCH: PATIENT B-7.

Julian suddenly gasped loudly beside Clara, his body contorting in a violent convulsion. His eyes snapped open, but they were no longer brown. A glowing, electric-blue ring had expanded around his pupils, illuminated by microscopic implants shifting beneath his corneas.

«Clara…» Julian choked out, his voice suddenly layering with a strange, double-toned resonance. He grabbed her wrist with terrifying, superhuman strength, his fingers digging into her bruised flesh. «Don’t let her… open… the inner door…»

«Julian! What’s happening to you?!» Clara cried, trying to pull away, but his grip was like an iron vise.

«He’s overriding his manual dampeners,» Eleanor said, her calm facade finally cracking into a look of genuine alarm. She slammed her hand down on a red emergency button on the glass desk. «Clara, drop him! Get down the stairs now!»

The floor beneath Clara violently shuddered. Above them, the heavy iron hatch they had just descended through began to warp inward, the heavy steel bending like paper under immense pressure from above. Someone—or something—was breaching the sealed blast doors from the terrace.

A loud, hydraulic hiss split the air as the glass walls of Eleanor’s vault slid open.

«He isn’t your husband, Clara!» Eleanor yelled over the rising shrill of alarms, reaching into her lab coat and pulling out a heavy pneumatic syringe. «The man you married died in the shipping yard fire five years ago! That thing sitting beside you is the prototype!»

Clara stared at Julian in absolute horror. He looked up at her, tears of blood leaking from the corners of his blue-lit eyes.

«She’s lying…» Julian rasped, but as he spoke, the skin along his jawline split neatly along a surgical seam, revealing a sliver of polished, silver alloy beneath his flesh. «Clara… I remembered… I remembered who I was…»

A violent explosion shattered the iron hatch above them, sending a shower of burning steel and concrete raining down the stairwell. Through the dense cloud of black smoke, a heavy tactical boot stepped onto the upper stair.

Clara looked up through the haze, her breath catching in her throat.

Descending the stairs through the fire was her mother, Evelyn—her clothes scorched, her face smeared with soot, but holding a heavy assault rifle leveled directly at Eleanor’s head.

«Stand down, Eleanor,» Evelyn growled, her voice sharp and deadly. «The autonomous flight sequence was a decoy. I’ve known about the subterranean vault since the day Arthur built it.»

Eleanor didn’t flinch. She raised the pneumatic syringe, aiming it squarely at the masked man on the gurney behind her. «Take one more step, Mother, and I flush the neurological bank. You’ll lose the ledger forever.»

«You won’t kill him,» Evelyn said, taking another heavy step down the stairs, her rifle steady. «Because you know as well as I do that the man on that gurney isn’t a patient.»

Evelyn pointed her weapon not at Eleanor, but directly at the oxygen-masked figure.

«Unmask him, Clara,» Evelyn commanded softly, her eyes never leaving Eleanor. «Unmask him and see who your sister has been keeping alive down here for five years.»

Clara’s mind raced, her body shaking uncontrollably between the half-synthetic husband holding her wrist and her armed mother on the stairs. She scrambled backward down the remaining steps, tearing herself away from Julian’s iron grip, and rushed into the glass vault toward the gurney.

«Clara, don’t!» Eleanor screamed, lunging forward with the syringe.

Clara dodged her sister, reaching out with blood-stained hands and snatching the heavy surgical bandages from the patient’s face, ripping them away in a single desperate pull.

The mask clattered to the floor.

Clara fell to her knees, the breath entirely sucked from her lungs.

Lying on the gurney, breathing steadily under the dim heart monitor, was an exact, flawless duplicate of Clara herself.

Before she could scream, the heart monitor flatlined with a solid, piercing tone, and every light in the vault instantly plunged into total darkness.

In the pitch black, a soft, familiar child’s voice whispered from the darkness right beside Clara’s ear: «Welcome home, sister.»