In a courtroom in Wellington, New Zealand, Barbara Leslie listens to testimony about her sister Delia and remembers the events that led to the trial: The Leslie sisters, Barbara, Anne and their impetuous younger siblings Evelyn and Delia, live in Christchurch, where most of the townsmen are preparing to leave for World War II duty, including their brother Kit and Barbara's new husband, Mark Forbes. With their mother deceased and their father lost to the war, the sisters console themselves by plotting their loved ones war locations on a world map in their living room. One evening, Delia gleefully announces her engagement to one of Christchurch's few remaining bachelors, "Shiner" Phil Friskett, but news of Kit's death quickly dampens her mood. Later, prim spinster Anne expresses her disapproval of the marriage, but Barbara defends Delia's happiness. Within weeks of Delia's marriage, the sisters come to hate Shiner's abusive behavior and are glad to see him leave for war duty. Delia, now lonely for male companionship, moves to the larger city of Wellington to work for the Navy despite Barbara's protests. When the United States sends several hundred Marines to Christchurch after the attack at Pearl Harbor in 1941, many of the men brashly flirt with the lonely New Zealand women. Naive, fourteen-year-old Evelyn cannot resist inviting kind Capt. Richard G. Bates to dinner. The well-mannered captain declines her offer, but not without attracting Anne's attention. Concerned that Delia has forgotten her marriage vows, Anne sends Barbara to Wellington, where Delia is registered at a hotel under her maiden name. After Barbara reports that Shiner is a prisoner of war, Delia introduces Barbara to her lover, an American lieutenant named Andy, and announces she plans to divorce Shiner and begin a new life in the United States. Barbara, shocked by Delia's adultery, is about to leave when Andy awkwardly explains that he was raised with the same family values as the sisters. Inviting her to join them at a Wellington bar, Andy introduces Barbara to his friend Jack Harding, a divorced and disillusioned soldier assigned to investigate the prospective New Zealand brides of American soldiers. Once alone with Jack, Barbara harshly criticizes the Americans for seducing New Zealand women with trinkets and money. Jack retorts that, although many of men have wives and children at home, "war makes strange bedfellows." When they share a wistful glance, Barbara, still faithful to her husband, is upset by her attraction to him and abruptly excuses herself. Later in Christchurch, Anne is outraged when the American soldiers make lewd suggestions at the lingerie shop where she works and writes a complaint, which is subsequently published in the local paper. One evening, Richard is sent to the Leslie home to deliver a formal apology for the Marine Corps' behavior. Charmed by his courtesy and his good looks, Anne invites him to dinner that evening, where Richard gives the sisters each a gift of perfume. Anne inadvertently reveals her interest in him when she expresses disappointment that someone she likes would use such a common ruse to seduce them. Days later, Barbara and Anne's hopes are dashed when they learn of Mark's death and Richard's departure for duty; however, when Richard returns to New Zealand to recover from an injury months later, a romance between him and Anne blossoms. Soon after, Richard proposes to Anne, but before the required marital investigation can take place, he is given offshore duty, leaving Anne pregnant and unsure of their future. Days later, Jack surprises Barbara at the Leslie home while reporting on his investigation of Anne. During their subsequent date, Jack explains to Anne that wartime romances are the product of loneliness not love, adding that he suppresses his loneliness with alcohol. Barbara finds his assessment heartless and returns home to find Richard's name on the latest casualty list. Weeks later, Jack finds Barbara at a town dance, where she cautions that his drinking is a coward's answer to intimacy. Jack finally breaks down in her arms during a stroll that evening, which begins a strong friendship between the two. Months later, on Christmas Eve, Jack celebrates with the Leslies, including Anne's newly arrived baby boy. In a moment alone with Barbara, when Jack announces his immediate departure for duty, their heretofore-suppressed passion erupts in an amorous embrace. Months later, Evelyn's New Zealand sweetheart Tommy returns from war and proposes to her. Despite her brief flirtations with American soldiers, Evelyn loves Tommy and leaves for Oakland with him. In a newspaper column containing personal ads from American families to New Zealand, Barbara spots an ad from Mrs. Bates, Richard's mother, and writes to her. In her reply, Mrs. Bates encloses money for Anne and her son to move to Oklahoma to be with Richard's family. As Anne's departure approaches, Delia flies down from Wellington to see her off and to meet Shiner, who has just returned from war. That night, when Delia does not deny Shiner's accusations of infidelity and demands a divorce to leave for America with her lover, Shiner flies into a rage and kills his wife with a Japanese sword he brought back from the war. Weeks later, during the murder trial, Jack is forced to reveal his investigation report detailing that Delia had had seven American soldiers as lovers. Traumatized and infuriated that her sister's infidelities have been made the scapegoat for the brutal murder, Barbara refuses Jack's offer to leave New Zealand with him. Upon returning to the lonely house, however, Barbara realizes that she is alone in Christchurch. After burning the map and packing her belongings, Barbara arrives at Jack's hotel room, where he embraces her. Overwhelmed by the new life she is about to embark on, Barbara notes that her father would be shocked by his daughters' lives, but Jack assures Barbara that her father would both understand and forgive them.