DI Matt Lockyer has been side-lined to working cold cases, following a bad decision he made in a recent investigation. Lockyer isn't too bothered though, as it gives him the chance to look into his own brother's senseless killing which still remains unsolved. On a quiet afternoon Lockyer receives a phone call from prisoner Hedy Lambert - a woman he put inside for murder fourteen years ago.

She informs him that the man she was originally accused of killing has turned up alive and well. She begs him to reopen her case. All those years ago, Lockyer had been the one to pin down Hedy's motive, but deep down he'd never wanted to believe she was guilty.

The thought that he might have sent an innocent woman to prison disturbs him, so Lockyer agrees to investigate. But has it become too personal and is he being manipulated? Perhaps there are some cases that should just stay buried.