Plot summary
In 1949 New Zealand, Wes Pennington and Cyril Kidman are two travelling con-men and gamblers who swindle bookies by taking advantage of delayed radio broadcasts of horse racing results. Arriving in the small town of Tainuia, the pair quickly fall out with the local bookie, Norm Cray, and decide to recruit a simple-minded but good-natured car yard worker, Don Jackson, to place bets with Cray on their behalf. Dinah, the beautiful wife of Don's boss Dick, catches Wes's eye, while Don admires a local waitress, Esmerelda.
Meanwhile, Sel Bishop, an unscrupulous landlord, is exasperated by a persistent trespasser on his homestead, the "Tainuia Kid", a Māori man with delusions of being a Mexican bandit. As an insurance scam, Bishop has arranged for Morrie, the drunkard brother of Bishop's partner Claire, to burn down Bishop's billiard hall in the town. However, Morrie and Claire – who believed the building was unoccupied – are horrified when the hall's elderly lodger, "Pop" Simon, dies as a result of the fire.
In collusion with Wes and Cyril, who make coded telephone calls to the town's pub, Don manages to win £1,000 from Cray. When he later discovers a note discarded by Don revealing the code, Cray realises he has been defrauded and angrily barges into Don's house, injuring Don's elderly father, who is home alone.
That evening, Sel Bishop hosts a dance for the townsfolk in his large woolshed. Enthused by Don's win, Dick has loaned Don a fine car to take Esmerelda to the dance. Wes attempts to seduce the flirtatious Dinah behind the shed, but they are discovered by her husband Dick, resulting in a fight. Over Cray's objections, Bishop allows Wes to use his share of Don's winnings to win a large sum at Bishop's illicit crown and anchor table, but the local police sergeant raids the shed and the crowd scatters, with Bishop refusing to hand over Wes's winnings. As the Tainuia Kid watches from the bushes, Cray pursues Wes and Cyril in his car, but when the pair flee across a nearby footbridge, Cray accidentally drives onto it, flinging Wes and Cyril into the river below. Don and Esmerelda spend the night in Don's car outside the woolshed.
The following morning, Claire has become anxious that Morrie has gone missing, and when she presses Bishop about this, he throws her out of the house. Don returns home to find his father angry about Cray's home invasion. A panicked Cyril arrives and tells Don that Wes has drowned. However, Wes wakes up on the river bank and is greeted by The Kid. Wes, Cyril, and Don are quickly reunited and befriended by The Kid, a merry but superstitious character who believes that a "Taniwha" (monster) haunts the river.
That night, Cray and Bishop join forces at Bishop's homestead and plot revenge. As Cyril, Don, and The Kid wait outside, Wes sneaks into the homestead, determined to snatch back his gambling winnings. When The Kid finds dynamite sticks in a nearby shed, he gleefully lights and throws several of them at the homestead, alerting Bishop and Cray to the presence of the men outside. Cray pursues them, and after a fight on the footbridge, Don throws Cray into the river. Inside, Wes overhears Bishop being confronted by Claire, who has learned that Bishop was aware Pop Simon was living above the billiards hall but allowed Morrie to set fire to it anyway. Bishop discovers Wes in hiding, and forces Wes and Claire at gunpoint into a meat locker where Bishop has imprisoned a drunken Morrie to prevent him from talking about the arson.
Bishop prepares to burn down the homestead by pouring gasoline around it, but is thwarted by Cyril and The Kid, who enable Wes, Claire, and Morrie to escape. During the ensuing struggle the homestead catches fire, and Bishop grabs what he thinks is a Gladstone bag containing his money. However, The Kid has replaced the cash with dynamite sticks, which explode, killing Bishop. The burning homestead collapses into the river.
As Wes, Cyril, Claire, and Morrie watch the explosion from afar, Wes laments that the money has been lost in the fire, but is delighted to find The Kid has rescued it. However, when The Kid catches sight of the burning homestead floating down the river towards him on the footbridge, he mistakes it for the "Taniwha", and – to Wes's horror – throws the banknotes into the river as an "offering".
In the final scene, the townsfolk attend an Anzac Day service. Don and Esmerelda smile at each other, as do the reconciled Dick and Dinah. Morrie and Claire are also in attendance. Cray arrives looking bedraggled, to the amusement of Don's father. The Kid, on horseback, salutes the service, while Wes and Cyril drive off in search of another town.
