I wasn't going to hurt her. The thought of damaging her produced the same revulsion I'd feel at taking a hammer to a Steinway. She was not a thing to be broken. She was a system to be tested under extreme conditions, and the test required her senses be reduced to a single channel.

Hearing. My voice. In the dark.

The elevator descended. The door whispered open. I walked the corridor to Suite 4, footsteps silent on the polymer-dampened floor, and keyed the override.

Absolute dark. The thermal overlay on my phone showed Elena sitting upright on the mattress. She knew I was there--could hear the displaced air, the faint creak of my shoe, the change in acoustic profile that a second body introduces into a sealed space.

"The piano was clever." My voice landed in the dark between us. "The resonant frequency calculation was within two hertz. I was genuinely impressed."

She didn't respond. Breathing controlled. The fear was there--elevated heart rate, slight tremor in her thermal outline--but held behind composure the way a dam holds water.

I crossed the room. In the dark, I could feel the heat radiating from her body. Warmth carrying the faint scent of clean skin and the ghost of the piano's wood oil.

"But I need you to understand something, Elena." I crouched beside her. The blindfold was in my left hand--smooth black silk, cool against my palm. "Every wall in this building listens to me first. Every frequency, every vibration passes through filters I designed before you ever woke up in this room."

I reached forward. My fingers found the curve of her jaw. The skin cool. The muscle tightening as she resisted the impulse to pull away.

I slipped the blindfold over her eyes. Not rough. Not violent. The controlled gentleness of a man who understands that the most effective restraint doesn't feel like punishment.

Her breathing stuttered.

In total darkness, the silk was redundant--she couldn't see anyway. But the physical sensation of fabric against her eyes, the weight of it, the intimacy of a hand that had just touched her face now drawing away--that was the variable. That was the data I was introducing into her model.

"Sleep now," I murmured, pressing the micro-injector against the inside of her wrist. Quick, painless. She would wake in four to six hours with a headache, mild nausea, and no memory of the transition. "Tomorrow the real lessons begin."

I stood.

Walked to the door.

Sealed it behind me.

In the corridor, I paused. My hand was trembling--a fine, involuntary vibration I stared at with clinical detachment. My heart rate, when I checked the armrest sensor back at the console, read eighty-nine.

I had touched her face. The skin beneath my fingertips had been warm, alive, taut with fear and defiance. The sensation had traveled through my hand and lodged itself somewhere behind my sternum with a permanence no architectural plan had ever accounted for.

The experiment was progressing. The subject was responding as hypothesized.

The experimenter was developing a flaw.