The body of a young woman is found in a stream. DI Cadi John a DS Owen Vaughan investigate her identity.

Cadi and Owen investigate a possible link to another girl who disappeared. Megan hides her difficulties from friends and family. Dylan takes an interest in Lowri.

Cadi and her sister Elin have an opportunity to discuss their father's future, and Dylan and Megan's lives collide when they are in the same place at the same time.

Iona's temper worsens as she punishes Nia and the police visit Dylan to question him.

Alun Pryce's anger boils over and he lashes out at a drug dealer, while Cadi and Vaughan take a step forward in their investigation as they visit a local reclamation yard.

The police finally succeed in getting the required information and this leads to some explosive events.

Will Cadi and Vaughan catch their man in the last in the series?