These days Sparkling Cyanide gets listed as the fourth Colonel Race book, but really, Race is a side character in every book he appears in. For example, the Race book listed as the third in the series is Death on the Nile where he acts as Poirot’s offsider. This book is really a standalone mystery, not part of any of the established series. Race does play a part in working out the mystery, but he is not the main detective and he does not solve the case.

A year before the events in this book, Rosemary Barton drinks a toast from her champagne glass, collapses and dies from cyanide poisoning. It seems impossible for anyone to have tampered with her glass, so the death is ruled suicide, even though no one who knew Rosemary would have thought her the type to do this. A year later, her husband, George, gathers the same group together for another dinner, at the same table at the same restaurant. A toast is drunk in memory of Rosemary and again, someone collapses and dies of cyanide poisoning. Again, it seems no one could have tampered with the glass. But this time, the police don’t believe it is suicide and start investigating both it and Rosemary’s earlier death as murder. Suspicion centres on the people at the table – Rosemary’s husband, her two lovers, and the wife of one of the lovers, her husband’s loyal secretary, and her little sister (who inherits all of Rosemary’s money). All of them have a motive for killing Rosemary, but there are no readily apparent motives for killing the second victim.

In writing Sparkling Cyanide Christie reused a plot she had previously used in one of her short stories, (Yellow Iris); something she did frequently. This one was a great plot to reuse, as there is a really great misdirection in Sparkling Cyanide that is really very clever. It’s not a complete repeat of the story, just at the point the explanation of how the murder was committed.

The second death doesn’t occur until we are over 50% in. The first half of the book focuses on the inner thoughts of the six people at the first dinner, of their memories of Rosemary, and of the dinner where she died. This is another demonstration of Christie’s cleverness as a mystery writer, as she includes the murderer’s thoughts among these, without any lies but without revealing what they know to be the truth. Sometimes what they don’t say is more important than what they do say! We get to know a lot about each of these characters, but we don’t really ever get to know much about Rosemary. She's pretty much left as the first victim without us learning anything to make us care for her in any way. But we do get to know all of the suspects, and get to decide which ones we like and which we dislike, and to decide which we think might be the killer. It was an undertaking in vain for me, I’m afraid, because Christie’s clever misdirection fooled me completely. I’m not completely convinced that the key point which explains what happens would actually work, but I’m willing to suspend disbelief and accept it. This is one of the ways I judge whether I like a mystery: if I’m happy to just enjoy the cleverness of the ending without bothering to think too much about whether it could actually happen. By that criterion, Sparkling Cyandide is one of those very clever ones.

Overall this was a clever, well written mystery and one that I really enjoyed.