Just one evil act - Elizabeth George

Goodreads 3.78

Sergeant Barbara Havers is at a loss: The daughter of her friend Taymullah Azhar has been taken by her mother, and Barbara can’t really help—Azhar had never married Angelina, and his name isn’t on Hadiyyah’s, their daughter’s, birth certificate. He has no legal claim. Azhar and Barbara hire a private detective, but the trail goes cold.

Azhar is just beginning to accept his soul-crushing loss when Angelina reappears with shocking news: Hadiyyah is missing, kidnapped from an Italian marketplace. The Italian police are investigating, and the Yard won’t get involved, until Barbara takes matters into her own hands — at the risk of her own career. 

As both Barbara and her partner, Inspector Thomas Lynley, soon discover, the case is far more complex than a typical kidnapping, revealing secrets that could have far-reaching effects outside of the investigation. With both her job and the life of a little girl on the line, Barbara must decide what matters most, and how far she’s willing to go to protect it.