In this first episode Gillian takes a forensic look at the police investigation launched just after Ruth's arrest. Gillian is all too aware of the femme fatale persona that has stuck with Ruth since 1955. She wants to build Ruth Ellis back up from the evidence and this means looking carefully at the police documentation from the time. Gillian begins with Ruth's first statement where she confesses to the crime, but intriguingly states that 'she's confused'. As Gillian follows the course of the investigation she uncovers some worrying assumptions, problematic omissions and missed opportunities. There's a key witness who was never questioned by the police - Ruth's 10-year old son Andre, who tragically took his own life in the 1980s. He left behind an audio cassette that features a recorded conversation where Andre shares his thoughts on his mother's case. Gillian uses this to piece together what the boy knew. Then there's the murder weapon; one of thousands of guns that flooded Britain during the war. Gillian traces its provenance and it leads her to a shocking conclusion. Experts in policing shed new light on the involvement of a possible accomplice and Gillian tracks down those who met Ruth and David. A picture begins to build of their relationship and lifestyle and it's a unique snapshot of the complex world of post-war Britain that made and then broke Ruth Ellis.