Who is stalking Mathias? Is it related to the murder of Aron Bowen? All will be revealed in the series' climax.

A burnt body on the dunes embroils the team in a long-standing family feud with a connection to the murder of a young mother 13 years earlier. Mathias is convinced the young woman's murder holds the answers, but Prosser isn't keen on Mathias delving into the past.

In a world full of dark secrets will Mathias and the team unravel them before another person is killed?

The discovery of a body in a lake leads to an investigation about a local primary school teacher.

Why did Nora and Daniel live such a secluded life? What has Mathias discovered in the garden?

The murder of a local dignitary and barrister leads to the uncovering of a tragic story of love and loss fuelled by distrust and suspicion in the depths of the Hinterland.

The team have an unexpected suspect to question, but Mathias knows he is unlikely to be the killer, while Mathias is fascinated by the life choices taken by ex-soldier John Bell.

The new series opens with Mathias under pressure. His wife Meg has turned up in Aberystwyth and he's under investigation by the IPCC following the death of Mari Davies at the end of the last episode. When a bus driver is found shot dead on an isolated mountainside, the investigation provides a welcome escape.