Young and charismatic priest Canon Zach Mantell shakes up Brokenwood's parish with his unconventional style. But when his wife dies in the church cemetery, Mike and Kristin find clues that point to a murder.

A celebratory vintage train ride ends in tragedy when a bride is murdered and thrown out beside the tracks. As Mike and his team investigate, they must dig through old rivalries and family tensions to find the killer hiding on the train.