The Vancouver lead had been another dead end. Maria Santos disappeared into the labyrinth of the city’s suburbs, leaving Damian with nothing but more questions and a growing sense of unease. Yet, it was the doctor’s name from the ultrasound that kept him awake at night, haunting him with its familiarity.

Dr. Sarah Chen.

He sat in his temporary Vancouver apartment, surrounded by papers and laptop screens.

“Marcus,” he barked into his phone. “Find everything you can on Dr. Sarah Chen.”

Within an hour, his security chief had compiled a preliminary report. Sarah Chen, now a respected OB-GYN in San Francisco, had maintained a low profile over the years. No...