This was the first of the Tommy and Tuppence books. It's pretty weak. It reads like a Hardy Boys book, full of adventure, danger, and oodles of implausibility. The characters do things rational people wouldn't do. I dunno, it was sort of cute in a way, but I expect something better plotted and written from Christie than I do from the pseudo Franklin W. Dixon. It probably deserves more than 2 stars, but it was so amateurishly done that I'm downgrading it.
This wasn't one of those typical drawing room mysteries, where baffling stuff happens and then all the suspects are gathered at the end for a discourse of the case and a fingering of the killer, usually accompanied by some hints that the rest of the suspects have skeletons in their closets. Nope, it's more of a spy thriller, but think spy thriller written for adolescent boys, except without all the gratuitous blood shed and with spunky young women.
I dunno, the more I think of it, the more I wonder how Christie got to be so famous. I love Poirot videos, but as much for the art deco settings as the stories, such as they are.