Case Sensitive

Charlie Zailer has to work with DC Simon Waterhouse for the first time after Geraldine Bretherick and her five-year-old daughter Lucy are discovered dead in their family home. They end up arguing as if to whether it is a murder case, suicide or something even more sinister. A woman ends up telling her best friend she was having an affair with Bretherick's husband and would like to see him once again.

A young woman calling herself Esther ends up visiting the crime scene. Charlie and Simon are able to find out the woman went on to a bird sanctuary but she ends up vanishing only leaving behind a picture of an unknown mother and child. After a woman's body is discovered floating in the river, Sally ends up realising that she is in great danger.