Tommy and Tuppence differ from Poirot and Marple (Christie's better-known detectives) in several crucial ways. They age at the same rate of their publications, with later novels set when they have been married for years and their grown children have left them. Their youth compared with the aforementioned detectives, as well as Tommy's war experiences and job, allow them to have more exciting and dangerous adventures than either Poirot or Marple.

This first adventure is definitely full of adventure and youthful enthusiasm. At the beginning of the novel, Tommy and Tuppence are still merely childhood friends, both down on their luck financially. They decide to form a "Young Adventurers" venture and advertise (much like Wodehouse's Psmith) that they will do anything, even crime, for enough pay. They soon get drawn in to a daring intrigue of treason and revolution.

The book reads as a thriller at times, with the protagonists engaging in disguise, car chases, and deceit among themselves, as they try to find a missing girl who holds the key to dismantling a revolution. Along the way, there is an amusing cameo from Inspector Japp, a recurring character in the Poirot novels. T&T also meet Albert, a young boy who becomes their assistant in future novels.

I thoroughly enjoyed reading this book, in spite of (or maybe because of) the multitude of overused thriller tropes. There were moments I had to suspend my disbelief when T&T pulled off something especially contrived. I was proud of myself, however, because this was one of only a few Christie books I've read where I managed to correctly guess the culprit.