In this familiar tale of a cop in search of redemption taking on human traffickers, Det. Tia Suarez, whom Griffin introduced in 2015's Benefit of the Doubt, persuades her boss to permit her to go back on the street, even though she has suffered from PTSD ever since being shot. Assigned to an undercover detail in Milwaukee, Wis., as part of a regional vice operation, Tia poses as a prostitute. Her first night, she's almost abducted by two bad guys. One of them, Gunther Kane, is caught, but the other man, who had a young girl captive in the back of a van, escapes. Tia is outraged that her account is questioned in court, and that Kane is let go with a slap on the wrist, despite having assaulted an officer. Though she has a history of hallucinations, Tia is positive about what she saw, and she will stop at nothing to find the kidnap victim. Griffin, a 25-year veteran of law enforcement, provides a sympathetic portrait of a decent cop trying to do her duty. Agent: Jill Marr, Sandra Dijkstra Literary Agency. (Feb.)