A past case comes back to bite DC Grace Dasari and she finds herself in a stand-off at a brothel with the distraught Kathy Merrill, who has a knife at the throat of Martin Taft, the man she believes knows what happened to her missing sister.

Six months ago, Kathy reported sister Lisa’s disappearance. Now she’s claiming that because Grace has done nothing to find the teenager, she’s conducted her own investigation. Lisa was on the game, so Kathy went undercover as a prostitute and discovered Martin was obsessed with Lisa. Grace persuades Kathy to let him go and, at the station, tells her colleagues, what she found out six months ago… Lisa went off the rails after her mother died, had an abortion and became a junkie. She got herself clean and Grace assumed she’d moved away to start a new life. But then her body’s found in woodland…

It’s starting to look as if Kathy was right about Martin, but then Grace discovers Lisa was having an affair with a teacher at her school, Brendan Newlyn (Ian Kelsey – Emmerdale, Casualty, Down to Earth). Questioned at the station, Brendan admits they were in the woods the night Lisa died and he left her there after they had a massive row. Under pressure from a furious Grace, Brendan cracks and tells her exactly what happened.