My sister and her boyfriend went on a trip to Europe, leaving her 10-year-old stepdaughter with me for a week. She smirked and said, "Don't get too attached to her. When I come back, she won't be my responsibility anymore." The moment the door closed behind her, the little girl whispered, "Aunt Harper... there's a secret I need to tell you." What she revealed made my blood run cold.

I didn't argue. I sprinted over to the couch, scooped Bailey up into my arms, and rushed toward the stone fireplace.

Caleb reached out, pressed a hidden lever behind the iron wood-holder, and a heavy slab of reinforced oak and steel slid open, revealing a small, lit bunker beneath the floorboards.

"Get inside!" Caleb yelled as the first volley of automatic gunfire shattered the front windows of the cabin.

RAT-TAT-TAT-TAT-TAT!

Glass rained down like hail over the hardwood floor. Bullets tore through the wooden walls, splinters flying everywhere.

I shoved Bailey down the narrow ladder into the dark bunker, dropping down behind her and pulling the heavy steel door shut above us.

The noise inside the small bunker was deafening. The muffled roar of Caleb's shotgun echoed from above:

BOOM! BOOM! BOOM!

Screams of pain, breaking furniture, and the relentless pounding of high-caliber rifles turned the tranquil mountain cabin into an absolute warzone.

Bailey covered her ears, shivering violently in the corner of the concrete room. I wrapped my body around her, holding her close, my heart beating so hard I thought my ribs would snap.

"Aunt Harper!" she sobbed against my chest. "Is Uncle Caleb going to die?"

"No," I declared fiercely, staring at the reinforced steel ceiling. "We are not going to lose today, Bailey."

Above us, the heavy sound of a body slamming against the fireplace echoed through the floorboards, followed by a heavy metallic groan.

Then, silence.

The gunfire stopped abruptly.

The silence hung in the heavy, gunpowder-scented air for ten agonizing seconds.

THUD. THUD. THUD.

Heavy footsteps walked slowly across the floor above our heads. They stopped directly over the concealed door of the bunker.

A voice spoke through the iron ventilation grate—a voice that made my soul freeze.

It was Jean.

"Harper?" Jean's voice echoed through the grate, cold, melodic, and entirely unbothered. "I know you're down there, sister. Caleb was very brave, but two men with shotguns can't stop six tactical contractors."

My heart stopped. Caleb.

"He’s still breathing, if that makes you feel any better," Jean continued casually, her high heels clicking against the concrete floor. "Though he won't be for long unless you hand over the drive and open this door."

I looked at Bailey. She was shaking her head frantically, tears spilling down her cheeks, pleading with her eyes for me not to move.

I reached down into my coat pocket. My fingers brushed against the secondary weapon Caleb had handed me earlier—a small, snub-nosed .38 revolver.

"Jean," I called out, my voice surprisingly steady as I raised my head toward the grate. "You murdered David. You poisoned him in cold blood."

A dry, bitter laugh resonated from above.

"David was a weak, paranoid fool who sat on a mountain of money he didn't have the stomach to spend!" Jean sneered. "He thought he could keep me trapped in a boring suburban life while he played god with his software! I built that life with him, Harper! I deserved half of everything!"

"So you decided to murder him and abuse his daughter?" I yelled back.

"Bailey is a mistake," Jean said flatly, her voice dripping with pure disgust. "She saw something she shouldn't have seen. I gave her months to forget, but she kept looking at me with those creepy, terrified eyes. She had to go, Harper. And now, you have to go too."

A heavy metallic click echoed from above.

"Marcus," Jean ordered softly. "Set the thermite charge on the steel door. Burn them out."

"Wait!" I shouted.

"You have five seconds to open that door, Harper," Jean said. "Five... four... three..."

I looked at the primary electrical junction box on the bunker wall. A thick red lever labeled EMERGENCY GENERATOR OVERRIDE / PROPANE VENT sat right beside the battery banks.

Caleb had built this cabin to survive a siege. The furnace system was connected to a three-hundred-gallon external propane tank, designed to vent excess pressure through the chimney if choked.

I grabbed the heavy red lever.

"Bailey," I whispered, pulling her flat against the concrete floor beneath a heavy steel workbench. "Cover your eyes and open your mouth."

I slammed the red lever down.

A loud, furious hiss of high-pressure liquid propane roared through the fireplace ventilation flues above.

"What is that sound?!" Marcus’s panicked voice yelled from above. "Jean, get back—"

"FIRE IN THE HOLE!" I roared.

I raised the .38 revolver, aimed directly at the iron ventilation mesh leading to the flue, and pulled the trigger.