"In her first undercover role with the agency, Isabella infiltrates a sex trafficking ring operating in the heart of London. Tom oversees the job, while also searching for the lunatic stalking Martha. With his attention pulled in two different directions, and the usually unshakeable Martha nervous and evasive, the pressure is on. Isabella's past trauma affects her performance on the job, triggering an argument with Tom that culminates in Isabella walking out and not coming back."