Roberta, Phyllis and Peter, three sheltered siblings, suffer a huge upheaval when their father, who works for the Foreign Office, is falsely imprisoned. The children and their mother, now penniless, are forced to move from London to rural Yorkshire, into a cottage near a railway line, where they befriend the railway porter, Perks.
Filmed at the National Railway Museum in York, featuring the original locomotive from the much-loved 1970 film.