Lynley and Havers try to solve the murder of one schoolgirl and the disappearance of another. Is a serial killer on the loose in suburban London? What is the mother of one of the girls hiding? And who is the mysterious redhead seen with both girls before they disappeared? Honeysuckle Weeks (Foyle's War) and James D'Arcy (Mansfield Park) co-star in this psychological chiller, which pushes the detectives' friendship to the brink and leaves one of them questioning a critical judgment call.