023: 'Twist of Fate'

In a Soho brothel, D.C. Grace Dasari faces Kathy Merrill who has Martin Taft tied to a chair, with a knife held to his throat. Kathy screams that she reported her sister Lisa missing six months ago and that Grace did nothing to find her. Kathy went undercover after finding out Lisa had become a prostitute and discovered that Martin was an obsessed client of hers. Kathy is certain he knows what happened to Lisa but is finally convinced by Grace to put the knife down and let the police officer do her job.

Back at the station, Grace tries to convince her colleagues that she did everything she could with the evidence available at the time. She explains that after Kathy and Lisa's mother died, Lisa's life spiralled out of control, resulting in an abortion at 16 and a heroin addiction. Grace had discovered Lisa had been clean for a while and assumed she'd left London to start a new life. However, when a body is found in a woodland area Lisa liked to visit, Grace and D.C. Jo Masters are forced to visit Kathy and her father Steve.

The pair are devastated when they identify Lisa's belongings and Grace swears she won't rest until she discovers what happened to Lisa…

As the investigation continues, the evidence against Martin begins to mount, leaving Grace in no doubt that he was the last person to see Lisa alive. Grace visits Kathy at home to tell her Martin is being charged with her sister's murder and apologises for not investigating more thoroughly in the first place. As they talk, Kathy shows Grace some pictures of Lisa that were found in her bag and the detective realises that two photos are missing from the developed roll.

Back at the station, Grace gets them developed and discovers the missing pictures are of Lisa and her school teacher, Brendan Newlyn, who helped them previously with their enquiries. Grace and Jo dig deeper and discover that Brendan was having an affair with Lisa and he was the father of the baby she aborted.

Brendan is brought in for questioning where he admits to the affair and the fact that he left her in the woods the night she died, after a huge argument. Grace becomes so furious that D.I. Neil Manson is just about to pull her out of the interview room when Brendan finally cracks and reveals what really happened the night Lisa died…