Written for serial publication in 1905, the book is a happy-sad story with a wonderfully fulfilling ending where justice triumphs and a happy family is reunited to be even happier than before difficulties beset them.
The introduction to my copy of the book says that Nesbit was inspired by the Dreyfus case to concoct this plot in which the father, a government employee, is arrested, tried, and found guilty of treason. The collapse of the family finances prompts a move to an inexpensive cottage in the country. Because the new house is near a railway line and not too far from the local station, the children become friends with employees of the railway and with one passenger in particular.
The book is old and old-fashioned. Mild fun is poked at the son who thinks he is superior to his sisters, but then common stereotypes of women and mothers prevail. The oldest child, a girl, is certainly brave, ingenious, and a leader, however.
I can't tell you how much I enjoyed this book. Everything was appealing, from the narrator, who turns to address her audience periodically, to the character of Perks, the railway porter, who is a good friend to the children -- and vice versa
Reading the beautifully illustrated Folio edition was a delight.