Detectives Amanda Andrews and Carl Hickman were partners in the NYPD unit that was tasked with fighting human trafficking. Both were highly skilled and widely respected for their professional endeavors. The two were exceedingly close, plainly romantically attracted to one another, and virtually inseparable. There came a day, however, when Amanda attended her father's funeral while Carl worked to save a child from Philip Genovese, a violent pedophile who kidnapped children and sold them into sexual slavery. Carl successfully rescued the kidnapped child, but in the process was shot in his right (dominant) hand by Genovese. The hand injury was disabling. Carl could no longer write with that hand, or hold a gun, or handcuff a criminal. He began wearing one black glove to hide his disfigured hand. Amanda blamed herself for not being with Carl when he was injured. Her guilt deepened when the NYPD fired Carl after his injury.
Carl moved to Europe to track Genovese to exact revenge for the loss of use of his hand and the resulting loss of the career to which he had dedicated himself. Unfortunately, he became addicted to the morphine patches which controlled his intractable pain. Notwithstanding that, Carl was recruited to be a member of a multinational crime-fighting organization affiliated with the International Criminal Court. This appears to have occurred as a result of outreach efforts quietly made by Amanda on Carl's behalf. Amanda became the team's liaison with the NYPD.
Over the course of several episodes, during which Carl and the team traveled to New York to pursue Genovese, and during which Amanda traveled to France to deliver Genovese to The Hague's prison, the romance between the two former partners deepens.