A 40-year-old billionaire had spent more than three million dollars trying to understand why his twin sons kept getting weaker, yet every specialist left his mansion with another theory and no solution. Then I arrived as their new nanny, got mocked by his arrogant private doctor, and noticed something outside the boys’ bedrooms that made me wonder whether the answer had been inside that luxurious house all along.

The silence in the subterranean corridor was absolute, broken only by the low hum of the emergency servers.

Marcus stared at Claire, his cold composure cracking for the first time as he looked closer at her face—the sharp jawline, the distinct gray eyes that mirrored his own.

"Claire," Marcus whispered, the name slipping out like a curse. "You're dead. You vanished into the NGO sector years ago."

"I didn't vanish, Marcus. I hid," Claire said, stepping forward, her voice ringing with icy clarity. "I watched you manipulate our father, destroy our family, and build an empire on corporate corpses. When I saw the private intelligence reports about the mysterious illnesses affecting Vincent Moretti’s sons, and realized your firm was quietly buying up Moretti’s medical patents at pennies on the dollar... I knew exactly whose hand was in the shadows."

Vincent looked sideways at Claire, stunned. "You knew who I was before you took the job?"

"I knew you were a desperate father who needed someone inside who wasn't on the board's payroll," Claire admitted without breaking eye contact with her brother. "I didn't know you, Vincent. But I knew your sons didn't deserve to be collateral damage in my brother's corporate war."

Marcus let out a dark, humorless chuckle. "How touching. A family reunion in a tomb. You really think waltzing in here with a handful of righteous indignation changes anything? Look around you, little sister. You're trapped in a concrete box with no way out, no signal, and two dying children."

"You underestimate my security protocols, Marcus," Vincent said, a dangerous smirk breaking across his bruised face.

Marcus frowned. "What are you talking about?"

"You thought you hacked my smart home," Vincent said, tapping his wristwatch—which suddenly flared back to life with a brilliant blue display. "You didn't hack it. You downloaded my trap into your own administrative terminal."

Before Marcus could react, the heavy steel security doors behind him slammed shut with a thunderous hydraulic hiss, locking automatically. Simultaneously, high-frequency sonic pulse emitters mounted in the ceiling activated with a shrill, piercing shriek.

The two mercenaries dropped their carbines instantly, clutching their ears and collapsing to the concrete floor in blinding agony. Marcus stumbled backward, dropping his tablet as the disorienting frequency scrambled his equilibrium.

"Now, Claire!" Vincent shouted.

Claire didn't hesitate. She lunged forward, sweeping Marcus’s legs out from under him and driving her knee into his chest, pinning him against the floor just as she had done to Blake earlier. She grabbed the fallen tablet, her fingers flying across the override interface.