Title: The Railway Children by E Nesbit
Plot description: When father is taken away by two men, Bobbie, Peter and Phyllis have to leave their lovely London home and go and live in the country with their mother and 'play' at being poor. They become fascinated with the local railway and friends with the people who work there. They have a series of adventures where they save the day and meet the man who will save their father.
Comments: I didn't enjoy this nearly as much as The Enchanted Castle. There were too many coincidences and things just fitted in a little too neatly. Also, as an adult living in the 21st century, I cringed at some of the dangerous activity around the railway line. Nonetheless, it is very well written and an enjoyable read.