In Spite of Thunder
A classic Carr set-up with some not-so-classic Carr elements, In Spite of Thunder is not Carr's best solution, but it is certainly one of his most enjoyable adventures.
Brian Innes has been tasked by his friend, the father of Audrey Page, with preventing Audrey from attending a gathering in Genevia held by Eve Ferrier, a former movie star, in Geneva. Audrey's father wants Audrey to avoid Eve because Eve is widely suspected in the public eye of murdering her (older, rich) fiance seventeen years ago. At the height of Hitler's power, Eve, her fiance, and two other Britons visited Hitler at Kehlsteinhaus at Berchtesgarden. Eve's fiance falls to his death off a balcony when the only other person on the balcony is Eve herself. The Nazi officers testified that Eve was nowhere near her fiance when he fell, but the public quickly figures out the Nazi officers hadn't seen anything and were just covering for Eve; Audrey's father naturally does not want her to associate with a murderess.
Also invited to the party are Sir Gerald Hathaway and Paula Catford, the two other British people present at Berchtesgarden on the fateful night. Eve has invited them to help prove her innocence, in anticipation of completing her memoirs. Paula says she actually did witness what happened on the balcony (and that Eve was nowhere near her fiance when he fell), but Gerald believes Eve murdered her fiance—and claims to know how she did it. The cast is rounded out by Desmond Ferrier, Eve's husband and a former stage actor, Philip Ferrier, Desmond's son by a previous marriage as well as Audrey's boyfriend and soon-to-be fiance, and finally a guest of Desmond—a certain Dr. Gideon Fell.
Brian manages to convince Audrey that this is obviously all a set-up for something not good. But since this is a murder mystery, Audrey ends up at the party anyway. Brian rushes to Eve's villa, and arrives just in time to witness a murder that seems to parallel the death at Berchtesgarden seventeen years ago.
I adore Carr's plots, but there's something about his writing that has always bothered me... It's something about his character's emotions. I'm sure Carr has particular emotions in mind for his characters for each line and conversation, but for whatever reason, I just cannot parse their thought processes. This gives me the impression that the characters in the book are just that: characters, rather than actual human beings. Which is not to say that I mind this! Mysteries in general are built upon chance and contrivance, and puzzle plots are my favorite kind. A good detective story must be crafted from carefully constructed pieces, and an actual person will just muddy things up; Carr's characters feel like dolls designed to develop a good mystery, rather than real, compelling human beings, but I'm reading this book for a good mystery, not compelling characters.
That being said, In Spite of Thunder presents an interesting exception. I won't say that they were compelling. But in a lot of mystery novels, the suspects feel like random people who got sucked into the incident and are simply trying to make it through without getting falsely arrested. In In Spite of Thunder, each character has their own agenda, their own set of information, their own thought process, and their own theory of what happened. And they act on these. This creates a complex, interesting set of interactions among the cast. While the characters don't feel "real," it does feel like there is something behind each of them, driving what they do.
One of the most consistent flaws I find in mysteries, especially with writers like Agatha Christie, is that at the end we are presented with a solution, rather than the solution. In other words, the solution we get makes sense and is perfectly consistent with the facts... but there's no reason we couldn't spin a similar tale where a different character is the killer. This is part of why I like locked room mysteries and other impossible crimes. Obviously, they certainly make a mystery more interesting and intriguing, but they also help address this issue. Another way to phrase my problem is that anybody could have committed the murder, and then one character seems to be arbitrarily designated the criminal. However impossible crimes flip this on its head, where it seems nobody could have committed the crime, and then we're shown how one character could have done it. Theoretically you could come up with an alternative method for some other character to pull off the impossible crime, but as long as you can't, then the solution presented does feel like 'the' solution.
John Dickson Carr has been called the master of the locked room, and most of his books feature some sort of impossible crime. Consequently, Carr's books rarely fall prey to this common error. In Spite of Thunder is again an interesting exception, as it features an impossible crime, and yet feels like 'a' solution rather than 'the' solution. The trick is often impossible for anyone but the killer, or has some other element to narrow down the suspect, but murder method in In Spite of Thunder could have been pulled off by nearly any of the suspects. The solution makes sense and is consistent with the other elements in the book (even the thematic ones!), and the murder method is certainly clever, but then the revelation of the killer feels underwhelming because there is so little actual evidence pointing to the killer's identity. The killer also has a small role among the main cast, and while they are obviously within the suspect list, their guilt likely would have had more gravitas if it had been of a character we were more familiar with.
The solution behind the murder method is simple and clever. I'm not entirely sure if the science/physics is actually correct, but Carr has what appear to be citations to a real book, and the solution is well within the bounds of reasonableness, so I think it's fine. The biggest issue is that the cluing might be a bit too subtle; it's quite easy to read over the vital clue during the very few times it's mentioned. The other main issue to me is that while the motive is thematically consonant with the book, a lot of it relies on assumptions or implications, without any hard facts or evidence to establish the situation that apparently led to the murder.
In Spite of Thunder is a romp. Carr is a master craftsman, and his skill is on display the entire adventure. We have an impossible crime, a parallel to a past death, the characters each trying to pull their own agenda, and through all this Carr keeps on presenting us with "meta-mysteries" (such as how a character can claim to have solved both murders, but can only explain one). Due to its flaws, the ending is only "good," but the journey to the end itself is great fun.