Roberta, Phyllis and Peter have their comfortable lives in London thrown into disarray by the unexpected disappearance of their father. They are forced to move to a small cottage in the countryside with their mother, who struggles to make ends meet by writing books. The children find solace in a stretch of railway track and the station nearby, and befriend the railway porter, who teaches them about running the station, and an old gentleman who takes the 9.15 train every day. Through this love of the trains they are led on many exciting adventures, including a quest to discover the secret of their father's disappearance.

One of the most popular children's books ever written, E. Nesbit's tale has enchanted generations of readers since it was first released in 1906. It has been adapted for the screen and the stage many times, and its story of innocence, intrigue and discovery remains perfectly poignant today.