You can still listen to BBC iPlayer Radio via your browser by visiting bbc.co.uk/radio
5/5 A surprising connection to the Old Gentleman promises a happy conclusion.
4/5 Bobbie knows the secret about her father and the children mount a rescue in a tunnel.
3/5 The children witness an accident on the line and courageously step in to save the day.
2/5 The children ask a favour of the Old Gentleman.
1/5 Bobbie, Peter and Phyllis's happy suburban life with their parents is about to change.