After the end of World War I, Australian soldier Jocko Wilson, Charles Laughton, admires the spirit of a destitute Belgian orphan who fights a larger boy. He feeds the child, whom he names “Nipper,” and the boy’s younger sister Mary, Donna Reed. When orders come to go home, he hatches a plan with his friend Ginger Gaffney, Clyde Cook, to smuggle the pair aboard the ship. Jocko also considers himself a protector and asks his singer girlfriend Aggie Dawlins, Binnie Barnes, to marry him. He bonds with Aggie but, in a drunken misstep, is nearly arrested and sails home without her.
Back in his homeland, Jocko buys a tavern and starts training the young Nipper for boxing, while Mary is sent away to a boarding school. The adult Nipper, Richard Carlson, rises to challenge the boxing champion of the British Empire, with Jocko betting heavily on the boy’s success even as Ginger warns him that one man cannot cover all bets. Mary finishes school, returns home, and the household breathes in a tense, hopeful rhythm.
In the climactic title fight, Nipper holds his own and fights with grit until a blow sends him crashing out of the ring. Realizing he’s injured his shoulder and cannot use one arm to the same extent, he nonetheless rises and delivers a shocking knockout that saves Jocko from financial ruin. The doctor privately urges that Nipper may never fight again, but Jocko keeps the grim truth from his son, choosing loyalty and optimism over fear.
With his profits, Jocko purchases an isolated hotel in Northern Australia, hoping to provide a quiet harbor for his family as Nipper recuperates. Father Polycarp, Arthur Shields, believes he can heal the shoulder, offering a glimmer of faith amid mounting debt as the hotel sits nearly empty. Then Aggie returns—not as the brash fiancée of the past, but as a wealthy widow who lends him money to pay creditors and, perhaps more riskily, to indulge gambling ventures. In a moment of desperation, Jocko wagers the hotel against all he owes Aggie in a game of craps. He loses, and Aggie’s revenge for being left at the altar lands with a quiet, bitter sting.
Meanwhile, Nipper encounters the journalist Dusty Rhodes, Stephen McNally, who had once covered his boxing triumph and is now pursuing Mary’s hand in marriage. The sight ruptures Nipper’s sense of family, and he momentarily lashes out, realizing that his feelings for Mary run deeper than brotherly affection. He departs without explanation, deepening the rift with his father just as Jocko plans another world-title match after Nipper’s shoulder has healed.
World War II reshapes their lives, and Ginger remains by the side of the family despite not enlisting at first. He pretends to be an officer to help, but in truth takes a construction job to aid the war effort. Fate brings him into the neighborhood when Japanese bombers attack the hotel. Ginger races back to the ruined place and crosses paths with a now-grown Nipper, who has joined the army. They confront the enemy together, and their courage helps free Aggie, Mary, and the children sheltering there from the intruders.
In a twist of truth that heals the old rifts, Aggie uncovers a long-sheltered fact: Mary’s and Nipper’s relationship is not that of siblings but of adopted siblings who shared a family, an important revelation that finally clears the way for their happiness. Belgium’s confirmation settles the last doubt, and the story closes on a note of renewed hope, family bonds, and the possibility of a future where love and resilience triumph over hardship.**
