The extent of danger the town faces unfolds. Aileen risks everything and when Diana and Richter finally face the murderer he has to conquer his demons if he wants to survive.

A murderer revealed, the race is on to find Sinead but when hope is lost, the case is closed until an unexpected return marks a new beginning.

With two bodies in the morgue, Richter and Diana make a discovery which connects Sinead and Ronan to a historical case called the Mountain Murderer.

Irish gangster Derry Fallon becomes a prime suspect in the couple's disappearance but when he remains elusive and Irish journalist Aileen Ryan disappears, the case begins to fall apart.

As Diana struggles with being on home ground. Richter fights his own demons as they both work hard to find Sinead and Ronan.

Irish Detective Theo Richter travels to a small town in New Zealand and teams up with Māori Detective Diana Huia to find a missing Irish couple.