She thought she knew everything about her sister. It seems she was wrong ...

DC Jo Boden was eleven-years-old when her older sister, Sarah, was brutally murdered during her first year at University. Her boyfriend, Nathan Wade, was convicted of the killing.

Now, 15 years later, Wade is being released on licence and documentary film-maker, Briony Rowe, says she can prove his innocence.

The Boden family has never recovered from the tragedy, and they have always been certain that Wade is guilty. But Jo, who grew up believing her sister was perfect in every way, starts to question the evidence which put Wade behind bars. And perhaps Sarah harboured some very dark secrets of her own ...