The Railway Children (TV) (2000)

The film opens in a happy, comfortable upper class home in London, in the early twentieth century. Roberta, Phyllis and Peter are the three children of a wonderful mother and father. One day the father, who works at the Foreign Office, is imprisoned as a result of being falsely accused of selling state secrets to the Russians. The children and their mother fall on hard times and eventually move to a poor cottage in the country, near a railway line. Fascinated by the railroad, wave the passengers every day, and their vigilance and courage prevent an accident. They keep the spirits up and find ways to help others. For their goodness, they befriend an important person who can help them to solve the case of his father.