The emotional story of a young woman's quest to discover the truth about her mother's death. Carol is about to get married, but feels she cannot move her life forward until she finds out who killed her mother 15-years earlier. This first episode focuses on her perspective as a teenager on the night of the murder, as well as her later obsession with the ongoing investigation and the policeman in charge, DI Hain.

A grown up Carol demands answers from DI Hain, who now relives that murderous night 15 years ago as the detective in charge of the case. Hain reveals a completely different story and new clues and secrets that the young Carrie did not see. In the present day, Carol persuades Hain to go back to London with her to reinvestigate the crime, but is his account of the past as complete as he claims?

With the help of retired detective Douglas Hain, grown-up Carol finally gets to learn the truth about her mother. They discover why Sally was murdered and who killed her, and uncover a secret world that she always concealed, but what is the price Carol and Hain will have to pay for the truth? Can Carol ever be reunited with the man she was about to marry?