Patea River, New Zealand, 1868: In a rebel Maori encampment, a young Maori woman, her older husband, a chief, and their two small boys are awoken by a warrior who warns of approaching soldiers. They flee across the river, but two days later are caught. A colonist soldier beheads the chief for the bounty, but is stopped from further murders by a captain and sergeant. The sergeant, FRANK HARDY orders the soldiers to take their captives to a nearby garrison, but they ignore him. As she is dragged away by her captors, the young woman looks back in horror as her boys are surrounded by loyal Maori troops wielding tomahawks.
Manawatu River, New Zealand, 1877: A Maori warrior watches two Scandinavian men cross a river. As one of the men drowns, the warrior remembers his mission – revenge for an atrocity that happened during the Land Wars of the late 1860s. The second young man is left shivering with terror on the opposite bank of the river, watching as the warrior performs a haka.
A Scandinavian settler asks mail coach driver, SERGEANT FRANK HARDY, late of Her Majesty’s 57th Foot to find out what happened to his missing brother and cousin, who were last seen crossing the Manawatu River. Hardy’s own horrific past experiences persuade him to accept the task.
Conducting his search, Hardy meets METTE JENSEN when she runs screaming from the bush into his path, escaping a threatening Maori who tried to take a piglet she killed. Later, attempting to divert her mind from a rape attempt by a fellow immigrant, Frank asks Mette to join him in the search for the young men, one of whom is her cousin. But first, he thrashes the would-be rapist.
Frank and Mette visit the local Pa (Maori village), where Mette sees someone she recognizes – the warrior who tried to take her piglet. Unsure about what she has seen she does not tell Frank, and as they leave the Pa the warrior attacks them, after first performing a haka. Frank drives the attacker away with a warning shot. He returns to town to organize a posse, but the warrior eludes them.
Mette takes Frank’s coach across the Manawatu Gorge to bring back a female relative whose husband has died. On the return journey they are confronted by the man who tried to rape Mette: Frank kills him with a tomahawk and they watch as the body falls into the gorge and is swept away.
At the Pa, a Powhiri is performed to welcome Frank’s old captain, now a land agent, in town to meet with Maori leaders. The warrior, hidden within the Powhiri squad, attacks again, but Frank brings him down with a rugby tackle. As the warrior is whisked away to a secret Armed Constabulary prison upriver, Frank discovers that the man was avenging his sister, the woman Frank last saw clutching the severed head of her husband, who was taken as a sex slave by the colonists and Kupapa (loyal Maori) troops. Meanwhile, the Pa is in trouble; the chief has sold the land to the government.
Frank finds the body of one of the Scandinavians, but the other remains missing. Frank and Mette are engaged. Frank plans to set up a Private Detective & Enquiry Office with WIREMU KARIRA, a Maori constable, and Mette accepts a position in a book shop.
An epilogue reveals the missing Scandinavian man died of cold, hunger and eating poisonous mushrooms with other local food in reach. His only chance of rescue is when he is seen by a young Maori boy across the river at the Pa, who shouts that he sees a Turehu, or white ghost. This claim parallels an earlier one by some Danish boys that they had seen a troldt in the bush – the warrior – underlining the fear and misunderstanding of the other that pervades the story.