The most terrifying phone call of my life didn't come from a doctor or the police. It came from my five-year-old daughter, Ava, routed through the pink smartwatch I’d strapped to her small wrist just that morning.

“Ava, my sweet girl? What's going on?” I answered, sitting in the dull glow of my computer screen inside my quiet corporate office.

For a second, there was only the hollow static of ragged breathing. Then, a muffled, wet sob that made my blood freeze.

“Mommy... Daddy's girlfriend hit me with a hockey stick.”

My ergonomic chair rolled backward so violently it slammed into a steel filing cabinet, sending a stack of manila folders cascading to the floor. “What?”

Ava sucked in a fragmented gasp, her tiny voice compressed into a terrified whisper. “If I cry... she'll hurt me again.”

Suddenly, a woman’s shrill, aggressive voice echoed in the background. “Ava! Who the hell are you talking to in there?”

I sprang to my feet, my keys spilling out of my handbag as my heart hammered against my ribs. “Baby, hide. Where are you?”

“The little bathroom...”

Trapped 27 minutes away in heavy afternoon traffic, I simultaneously dialed 911 on my desk phone and my sister, Dana, on my cell. Dana lived only eight minutes away from my ex-husband’s townhouse. She was also a former professional MMA fighter who spent her days running a combat sports gym.

Before Dana could answer her phone, the girlfriend’s voice detonated through Ava's watch speaker. “Give me that damn thing!”

Ava let out a blood-curdling scream, followed by a heavy, sickening thud and a sharp, pained whimper. Then, the connection dropped, leaving only dead air.

“Dana!” I screamed into my phone, bursting through the glass doors of my office building into the parking garage.

“I'm in the driveway,” Dana’s voice came through the line, completely devoid of emotion—a flat, predatory whisper. “There’s screaming coming from the second floor. I'm not waiting for the cops.”

I heard Dana’s heavy fist hammer against the solid wood of the front door. “Marissa! Open this door right now!”

No verbal response came from inside. Only another muffled, agonized wail from my five-year-old child.

“Hold on,” Dana growled.

A catastrophic, violent splintering of wood and metal shattered the audio feed as Dana landed a devastating kick directly beside the deadbolt, throwing the heavy front door completely off its hinges. She was inside.

I threw myself into the driver's seat of my SUV, slamming my hand onto the steering wheel. “Dana! What do you see? Is Ava okay?”

The absolute, dead silence that followed on the phone line was the most terrifying sound I had ever heard in my life.