32 Weeks Pregnant, I Watched My Husband Bring His Mistress to Christmas—Then I Said, “Since You Brought Someone, I Brought Someone Too.”

The basement of the Dre estate was a sprawling labyrinth of 19th-century fieldstone arches and modern steel reinforcement beams. Pipes clanked overhead, carrying pressurized steam through the belly of the house.

The smell of gasoline was overpowering down here. It hung thick in the air, stinging my eyes and catching in the back of my throat. I covered my nose with the silk hem of my dress, stepping carefully behind Mercer over the damp concrete floor.

Thirty feet ahead, illuminated by a single flickering halogen work light, stood Fiona Vale.

Her ivory gown was ruined, splattered with black grease around the hem. She had discarded her high heels and was standing over the unconscious body of old Thomas, the estate’s groundskeeper for thirty-five years. A heavy iron wrench lay on the floor beside him, slick with dark crimson.

Mounted against the main support pillar of the mansion was a series of four industrial plastic drums, wired together with thick copper cables leading to an electronic receiver blinking with an ominous red LED counter.

*00:14:22.*

Fourteen minutes.

"Drop the detonator, Fiona!" Mercer commanded, stepping into the light with his weapon aimed squarely at her chest. "Step away from the pillar! Hands where I can see them!"

Fiona didn't jump. She didn't scream.

Slowly, she turned around. A cold, mocking smile spread across her red lips. She reached up with one hand and casually fingered the diamond necklace Matthias had bought her.

"Detective Mercer," she purred, her voice dripping with venom. "I wondered how long it would take you to find the breadcrumbs Serena left. You really are predictable."

"Step away from the console," Mercer repeated, his voice like iron.

"You shoot me, Detective, and my thumb releases the dead-man switch in my pocket," Fiona said, raising her left hand slightly to reveal a small black transmitter nestled in her palm. "The signal broadcasts instantly. Fourteen minutes turns into zero seconds. And eighty people upstairs—including the glorious Charles Dre and his pathetic, gullible son—become ash."

"Fiona," I called out, stepping out from behind Mercer into the glare of the work light.

Her eyes flicked to me, and for the first time, a flash of genuine hatred broke through her composure.

"Serena," she sneered, looking down at my stomach. "The saintly, long-suffering wife. You really thought you were clever, didn't you? Bringing the police to Christmas dinner. Did you think you were saving your marriage?"

"I don't give a damn about my marriage," I said, my voice steady, ringing through the stone arches. "Matthias is a spineless, greedy parasite. You can have him. What I care about is the fact that you’re about to murder eighty innocent people, including the staff who served your champagne upstairs."

"Innocent?" Fiona laughed, a sharp, hysterical sound. "There are no innocents in this house! Charles Dre stole my father’s company twenty years ago, drove him to put a bullet through his head in a cheap motel, and built this entire dynasty on the ashes of my family! And Matthias..." She scoffed, her lip curling with disgust. "Matthias was so desperate to escape his father's shadow, so desperate to prove he was a ruthless businessman, that he swallowed every lie I fed him. He thought we were going to run away to the Caribbean. He doesn't even know his own jet has a flight plan registered only for one passenger."

"He's upstairs right now," I said, stalling, calculating the distance between Mercer and the support column. "He thinks you love him."

"He's a fool," Fiona snapped. "And in thirteen minutes, he'll be a dead fool."

Just then, the heavy steel door at the top of the stairs creaked open.

Heavy, erratic footsteps tumbled down the iron stairs.

"Fiona?! Serena?!"

Matthias stumbled into the light, his bow tie undone, his face slick with sweat. He froze, his gaze darting wildly between Mercer’s gun, Fiona’s grease-stained dress, the unconscious groundskeeper, and the bomb wired to the foundation of his ancestral home.

"What... what is this?" Matthias stammered, clutching the iron railing. "Fiona... you said it was just a small incendiary device in the storage room... you said nobody would get hurt... you said we had until midnight..."

Fiona looked at him like he was a cockroach on the kitchen floor.