The safehouse was quiet except for the soft hum of diagnostic equipment. Jesse Ferrari sat motionless on the maintenance bench, her left arm extended beneath the overhead work lamp. The synthetic skin had been peeled back from her forearm, revealing the intricate lattice of carbon-fiber struts and neural interface nodes beneath. She ran a calibration probe across the exposed circuitry with mechanical precision, her human right hand steady despite the tremor she'd been experiencing for three days.

A fragment of memory surfaced unbidden—a classroom, sunlight through windows, a teacher's face she couldn't quite reconstruct. Jesse's jaw tightened. These weren't her memories. They came from the neural implant's background processes, ghost data from archived personalities that the military had loaded into her system years ago. They happened less frequently now, but each one felt like someone else's life bleeding into her own.

She pushed the thought away and focused on the work. The servo response in her left index finger was reading 3.2 milliseconds slower than optimal. Unacceptable. In her line of work, three milliseconds was the difference between a clean extraction and a body bag.

The secure communication device on the bench chirped once—a sound like a bird with a mechanical heart. Jesse didn't look up from her work, but her enhanced auditory implants were already processing the encrypted handshake protocol.

"Ferrari." Commander Walsh's voice came through the speaker, clipped and urgent. "We have a situation."

Jesse set down her calibration probe and reached for the communication device with her right hand, her synthetic arm still exposed to the work light.

"I'm not scheduled for deployment," she said flatly.

"This isn't scheduled." A pause. Through the encrypted channel, she could hear the background noise of the command center—multiple voices, alert klaxons in the distance. "We've got an activation signal coming from a Cold War facility downtown. Penthouse lab in the ruins sector. The system's been dormant for forty-three years."

Jesse's breath steadied. She'd been waiting for something like this—the military always had classified ghosts waiting to wake up. "Which system?"

Walsh's hesitation told her it was bad. "Sentinel."

The name hung in the air between them like a threat.