My sister stole my custom wedding gown and walked down the aisle in it—so I let nearly 300 guests watch the security footage that revealed who helped her.

The descent into the lower foundations was like stepping back into the nineteenth century.

Beneath the manicured lawns and polished marble floors of the modern Laurent estate lay the vaulted brickwork of the ancient Lyon textile cellars. Julian used the tactical light on his smartphone to carve a narrow beam through the thick, musty air. Cobwebs hung like rotting lace from the arched limestone, and the smell of damp clay and machine oil choked our lungs.

Behind us, distant explosions rattled the foundations. Beatrice’s mercenaries were breaching the upper estate, systematically destroying the evidence of their failure.

"How long have you been working for the French Ministry?" I asked, struggling to maneuver the heavy volume of my gown through the narrow corridor. Julian kept his arm around my waist, lifting the heavy hem to prevent it from dragging in the puddles of stagnant water.

"Since 1998," Thomas answered, his eyes scanning every shadow, weapon raised at the low-ready. "After the mill burned, I washed ashore near Marseille. I had third-degree burns and no documentation. When the intelligence services discovered what Arthur had stolen from the military prototypes, they offered me a deal: help them trace the black-market synthetic network, or spend life in prison as an accomplice to treason."

"So you abandoned Clara," Julian said sharply, his voice dripping with anger on my behalf. "You let her grow up in cold rooms, sewing buttons for Eleanor until her fingers bled."

"Every month, Julian, an anonymous envelope containing ten thousand francs was deposited into a blind trust under Clara’s legal name," Thomas replied without turning around. "Arthur intercepted every single payment. He used her inheritance to fund his own lavish lifestyle and buy Eleanor her debutante gowns. I was deep undercover in South America for twelve years. By the time I returned, Clara was already eighteen, running her own boutique, completely isolated by Arthur’s web of lies."

"He told me my father had committed suicide after going bankrupt," I whispered, the cold stone scraping against my shoulder as we reached a heavy iron door reinforced with bronze rivets. "He made me feel grateful for every scrap of food he gave me."

"Arthur is a parasite," Thomas spat. He reached into his pocket and pulled out a heavy, multi-toothed iron key. He inserted it into the ancient mechanism. With a grinding groan of ungreased gears, the lock turned. "He lives off the genius of artists while convincing them they are worthless without him."

The heavy door swung outward, revealing an enormous subterranean cavern lit by battery-powered emergency strip lights.

I gasped.

The room was not a cellar; it was a museum frozen in amber. In the center stood a massive, four-story Jacquard mechanical loom, its wooden punch-cards cascading from the rafters like an endless paper waterfall. Spools of thread, shimmering with a natural, unearthly golden hue, lined the perimeter walls in hermetically sealed glass cases.

And on a wooden tailor's mannequin standing right before the loom sat an identical wedding dress.

Except this one was not white. It was woven in deep, midnight black, embroidered with silver threads that seemed to pulse under the dim electric light.

"The Mourning Dress," I breathed, walking forward as if pulled by an invisible thread.

"Vivienne’s masterpiece," Thomas said, lowering his gun slightly. "She knew Arthur was coming for her that night. She spent her final forty-eight hours weaving the complete encrypted source code of the synthetic formula into the weft of this black gown. Every knot, every tension variation, represents a line of molecular code."

"Which means," a sharp, venomous voice rang out from the shadows near the back of the chamber, "whoever holds this dress owns the future of military composites."

From behind the massive wooden frame of the loom, a woman stepped into the light. She was dressed in an elegant charcoal pantsuit covered in dust, her silver hair pulled back into a severe bun. In her gloved right hand, she held a silenced semi-automatic pistol aimed straight at my chest.