A British doctor hires an injured ballerina as a nanny for his son.

In a small English town in 1914, Dr. David Newcome meets Leni, an Austrian girl, after she is injured in a theater while dancing. When he returns to see her, Leni has gone. David encounters the girl once more after she attempts suicide, and he engages her as a governess for his son Gerald, a young boy with an overactive imagination and an unsympathetic and harsh mother. Gerald adores his new governess, but gossip and misunderstanding divide the household and Gerald's wife Jessica takes her son to live with his uncle until the governess leaves the house. When war hysteria breaks out, David, afraid for Leni's safety, arranges for her to leave the country. Meanwhile, returning home to retrieve his pocket knife, Gerald accidentally breaks a bottle of pills and puts the scattered tablets into another bottle. That night, Jessica takes the pills, believing them to be headache tablets, but they are actually poison and the next morning, she is found dead. David and Leni are arrested for her murder, and when David can give no explanation for the transfer of the pills, they are found guilty and sentenced to be hanged. Destroyed by circumstantial evidence, the couple approach death knowing that they are not alone, but will be joined by the multitude of innocent young soldiers sacrificing their lives on the altar of war.