Unlike many of the other Secret Seven books that I have read, this one pretty much launches straight into the adventure. The reason is probably because this one is a little more complex than a lot of the other adventures where Blyton seems to use the beginning as a sort of filler for a much shorter story (though as I think about the previous one, Three Cheers, Secret Seven, the filler sets the scene for the adventure). Right from page one the Secret Seven are given a mystery by their Dad to solve, namely that a young girl has gone missing after some money was stolen from her teacher, and it is up to the Secret Seven to find her.
There is a further difference with this book as the mystery is public knowledge rather than them stumbling onto something that nobody else knows about. The police are also actively involved in attempting to find the girl (as is Susie when she discovers the mystery – which is interesting because Susie claims that she has solved it, but we never find out if she actually had solved the mystery, or was simply playing games as she is want to do).
It is difficult to know what to write about these books this far into the series because while they are not necessarily the same, it feels difficult to actually get all that much more out of the story without simply giving a synopsis (which I won't do because that would give too much away). However, I am not sure whether this is a book where I could really delve into the issue of youth homelessness and street kids. Mind you, it was written in 1957, and the impression that we get is that youth homelessness was something that wasn't really written about, or even discussed.
What we have here are upper middle class children solving mysteries in an upper middle class world. While most of them involve criminal elements piercing this world, and the children putting an stop to these nefarious deeds, so as to maintain the illusion of tranquillity in the world, we don't see much beyond this few characters. Even our run-away (who is innocent, but we suspect that anyway) is a member of the upper middle class, and what the Secret Seven are in effect doing is going out to clear her name (even though they don't realise it at first). Even while Susie may be annoying, she is still a member of this class, so while she may be spiteful and prone to playing tricks on the Secret Seven, there is still that element of goodness about her.
Thus, being a child and being immersed in such stories gives us the picture of a tranquil world that is only occasionally pierced by criminal elements. Here the children are allowed to not only run around their town and the surrounding countryside, but they are also able to confront and challenge the criminal element with no real danger. Even then, some of these elements have innocent purposes anyway, such as in Three Cheer's Secret Seven, where the criminal activity ended up having a noble purpose (and I won't say what that was because I didn't say that in my commentary of that book).
So, it is interesting contemplating on the world of Enid Blyton's mysteries because the the world seems to be a good world with good people that is only occasionally affected by bad elements. I guess that is one of the reasons why the older generation looks back at the bygone era and moans about how bad the world has become when in reality that bygone era was really only an illusion.