MY 6-YEAR-OLD HEARD A WOMAN CRYING UNDER OUR MARBLE FLOOR—WHEN WE SMASHED IT OPEN, WHAT WE FOUND FROZE MY BLOOD!

The morning sun gave no warmth when I returned to the house. The driveway was choked with police cruisers, a mobile crime scene unit, and Miller’s unmarked sedan. Crime scene tape fluttered violently in the biting autumn wind, yellow ribbons slashing across my manicured boxwood hedges.

I stood on the driveway, staring up at the house. For ten years, I had viewed Blackwood Manor as a sanctuary—the place I bought to rebuild my life after my wife Sarah died of cancer. Lily was only a toddler when we moved in. I had watched her take her first real steps on that marble floor. I had celebrated seven Christmases under that crystal chandelier.

Now, looking at the high, arched windows of the second floor, the house felt monstrous. The glass panes looked like dead eyes reflecting the gray sky.

"Mr. Ward," a technician in white Tyvek coveralls called out from the front door. "Detective Miller wants you in the study."

I walked inside. The smell of dust and old concrete from the opened hatch still hung heavy in the air. The hole in the foyer had been marked with orange traffic cones, a temporary plywood board laid loosely over the mouth to keep anyone from falling in.

In my study, Miller had spread three large blueprints across my mahogany desk, weighing down the corners with my bronze bookends.

"Take a look at this, Daniel," Miller said without looking up. He looked haggard, his fingers stained with graphite. "Clara wasn't hallucinating from oxygen deprivation. She was telling the absolute truth."

He tapped a diagram showing the second-floor master bedroom—my room.

"Look at the exterior wall thickness," Miller pointed out. "A standard exterior residential wall is six to eight inches thick. Here, the outer brick layer is separated from the interior plaster by a forty-eight-inch cavity. We thought it was insulation or old dumbwaiter shafts. It’s not."

"What is it?"

"It’s an internal catwalk system," Miller said grimly. "Every room on the second floor is flanked by narrow maintenance corridors made of treated pine and acoustic felt. A grown man could walk from the attic all the way down behind the pantry without ever setting foot in an open room."

My stomach lurched violently. I thought of all the nights I had sat alone in the dark, sipping scotch, mourning Sarah. I thought of the faint creaks I had dismissed as settling timber. I thought of Lily waking up at three in the morning, complaining that the walls were "snoring."

"Julian Vance was an eccentric architectural theorist in the late 1980s," Miller explained, pulling out a manila folder. "He wrote manifestos about panoptic living—how human behavior changes when individuals believe they are completely alone versus when they are secretly observed. He inherited billions from his father's industrial empire and poured it all into this place."

"Vance disappeared twenty years ago," I said, my voice rising in panic. "The state declared him legally dead!"

"His body was never found," Miller countered flatly. "And someone has been paying the auxiliary utility bills for an off-grid electrical feed buried beneath the carriage house for the last decade. It runs directly into that subterranean chamber."

"Where is Thomas?" I suddenly asked, the realization hitting me like a cold bucket of water. "Where is my groundskeeper?"

Miller froze. He looked up from the blueprints, his eyes narrowing. "Thomas? The older man who helped you pry the hatch open yesterday?"

"Yes! He’s lived in the carriage house at the back of the property since before I bought the place. The estate sale agreement had a life-tenancy clause for him as a groundskeeper. He told me he was just an old employee who came with the land!"