On the surface what seems to be just a children's mystery/thriller with good characterizations of young adults struggling with issues that exist in any time period is also full of deeper issues. There are very well written moments of suspense when Noel and Phil are cornered in a barn while a suspected arsonist is hunting them and when Kitty hides in a room waiting as steps get closer and the door slowly opens. How many classic horror films and thrillers have scenes exactly like that? Overall, the kids are likable with typical problems and flaws but they are not equally well developed. In particular, Noel Wix seems bland and there is not much to make him memorable or distinguishable from other characters other than he shows up a lot more often than the background characters. Irene, Phil, and Kitty have more moments when you get a sense of their character.
It is a surprise how many issues are actually packed into this book (and handled well): empire, the role of women, race, jingoism, mob mentality, education, the rights of individuals vs. the rights of the public regarding property, and socio-economic classes. Based on just the subject matters touched on in this book it could be set in present day just as easily as in the middle of WWI. However, I didn't feel like this was a book that was suppose to be about issues with a just a loose narrative linking them together and to preach a particular view point. Some issues are touched on lightly and young readers may not pick up on them at all. This did not leave me disappointed. Not everything needs to be beaten over the head by mentioning it multiple times or putting neon lights around it to highlight it. Some things and events can just be there in the background to be explored more if one wants or just to give a taste of the time and context.