Chris McCowan believed his wife Angela had been abducted, but he had no way of being sure. She was an MI6 agent and routinely didn't check in with him for weeks. His intuition told him something was different this time.
He was an American computer scientist living in Angela's home in Bath, England. He worked on cyber security for the FBI, and he'd had investigated missing people before. While illegally analyzing FBI computer communications with MI6, he found a reference to an agent missing and per the faintly encrypted description, the missing person could only be Angela.
What to do? She'd made him promise to never go looking for her if she was missing. A promise he couldn't keep. Chris activated the Vengeance Squad. Tex, one of his students who understood the seedier side of the world and Liz, the retired librarian who could find the resources needed to carry out a search anywhere in the world. They'd worked together before and had successfully completed the missions.
A clue that takes them to a refugee camp in Berlin where they are joined by Heinz, a German translator. Liz's financial backers provide a bookmobile outfitted with the latest technology to help find Angela. When they finally find her, they must convince her to leave her captors.