The police have finally acknowledged that Bea's sister Tessa was murdered, and didn't commit suicide whilst in the grip of post-natal psychosis. Bea is convinced that the key to her death lies with the Cystic Fibrosis gene therapy trial she had taken part in, and has been given hope by William, a doctor from the hospital where Tess had her baby, who has not only become a partner in the hunt for the truth, but has made his attraction to Bea quite clear. As she closes in on the killer, there's a dreadful shock in store for Bea.

Abridged by Lauris Morgan-Griffiths and read by Hattie Morahan.
Produced by Sara Davies and Christine Hall. Show less