On Christmas Eve, I watched my father-in-law hurl a crystal glass at my mother-in-law's head.

"Into the server room," I whispered, shoving Martha through an unmarked heavy steel door to our left.

I slammed the door shut, throwing the mechanical deadbolt just as the first suppressed round punched through the center wood panel, sending a shower of splinters across my face.

The server room was freezing, cooled to fifty-five degrees to protect the rows of humming mainframes that processed the entire building’s communications. Red backup LEDs bathed the room in a bloody, surreal glow.

"Sarah... they’re going to kill us," Martha gasped, pressing her back against a metal rack of humming hard drives.

"They have to get through this door first," I said, my mind operating at hyper-speed, processing variables, angles, and choke points.

The door was rated for fifteen minutes of fire protection, but against specialized breaching charges, it wouldn't last sixty seconds. We were on the third floor. There were no exterior windows. The only exit was the service ventilation shaft or the maintenance elevator, which was currently locked out from the master breaker.

I ran to the main terminal console, pulled a thumb drive from my pocket, and jammed it into the master interface port.

"What are you doing?" Martha asked, tears running down her cheeks.

"I’m turning the building against them," I replied, my fingers flying across the mechanical keyboard.

Robert had installed a multimillion-dollar automated fire suppression and security system throughout the tower—a system designed to seal off sections during an emergency to protect executive personnel.

On the other side of the heavy door, I heard the telltale *clack* of a magnetic breaching charge being attached to the steel frame.

*Five seconds.*

I bypassed the security protocols, routing the building’s primary HVAC fire suppression controls directly to the third-floor executive corridor.

*Three seconds.*

"Cover your ears!" I yelled at Martha.

*One second.*

*BOOM!*

The server room door blew inward with a deafening blast of heat and flying shrapnel. Smoke and dust billowed into the room.

Through the haze, the silhouette of the first Blackbriar operative emerged, his weapon raised, laser sight sweeping the racks.

I didn't shoot. I hit the `ENTER` key.

Instantly, the high-pressure Halon gas fire-suppression system engaged in the corridor outside. Thousands of cubic feet of oxygen-depleting gas vented into the hallway with a roar like a jet engine.

The operative in the doorway gasped, his eyes widening through his tactical goggles as the atmospheric pressure in the corridor plummeted. The two men behind him dropped their weapons, clawing at their throats, suffocating instantly as the oxygen level dropped to near zero.

The lead operative tried to step into the server room to reach breathable air, raising his submachine gun toward my chest.

I didn't hesitate.

I grabbed a heavy, ninety-pound lead-acid backup battery from the charging rack beside me and hurled it with all my strength straight into his face.

The heavy battery struck him square in the mask, shattering the composite frame and driving him backward into the suffocating cloud of Halon gas in the hallway.

He collapsed onto the floor, twitching feebly, before falling motionless beside his team.

I slammed the broken door shut, locked the secondary latch, and grabbed the operative’s dropped radio from the floor.

I keyed the mic. "Elena. The third floor is clear. Tell Miller to send the federal tactical team to the north stairwell right now."

Elena’s voice crackled through the static: *"Sarah! Federal agents are breaching the mezzanine now! Hang on!"*

Ten seconds later, the unmistakable sound of flashbangs and authoritative shouts echoed through the hallway outside.

"Federal agents! Drop your weapons! Down on the ground!"

The heavy door was pulled open from the outside. Special Agent Miller stood there, rifle raised, his eyes scanning the room before lowering his weapon.

"Mrs. Sterling?" Miller asked, out of breath. "Are you alright?"

I looked down at my blood-splattered hands, then looked over at Martha, who was sitting on the floor, breathing heavily, but alive.