When Amy Whyte and Penny Brogan leave a local nightclub in the early hours of Sunday morning and don't arrive home, their families are beside themselves with worry. Conor Dowling has just been released from prison, a man full of hatred for Amy, the girl who put him behind bars. The case is given to Detective Lottie Parker when the girls' blood-soaked bodies are found, days later, in a derelict squat. Chillingly, both girls are clutching silver coins in their hands. All the signs point to Conor but his alibi is water tight. As Lottie examines Penny and Amy's final days alive in a desperate search for clues, two more girls are found stabbed to death in a luxury apartment complex. Caught up in what is fast becoming her toughest case yet, Lottie is unaware that somebody is watching her every move.