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.

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.