On a cold December night in 2004, Sarah Green got out of a taxi at the end of her cul-de-sac and was never seen again. Catherine Green joined the Police to find her sister, secretly copying case notes and scavenging scraps of information that formed part of the original investigation. But seventeen years after she disappeared, there isn't much hope that she'll ever be found. When Sarah's body is unearthed on a construction site in the centre of Cardiff Catherine is distanced from the case by her superiors, forcing her to enlist local Private Investigator Damien Owens to help find the truth about Sarah's final moments - and catch a killer who's escaped justice for almost two decades.