AYUKAWA Tetsuya was a leading representative of the traditional detective story in the decades after the second world war. I wasn't very keen on his The Villa Lilac Murder Case; but 黒いトランク (kuroi toranku, The Black Trunk, 1956) seems to me a real classic of the alibi breaking genre. It is fairly explicitly a homage to Freeman Wills Crofts' classic The Cask (1920), but its complex and ingenious plot makes it a masterpiece in its own right.
The story starts with the discovery of a dead body in a trunk delivered to a Tokyo station from northern Kyuushuu. The addressee has never appeared to collect it, and the address given seems to be a fiction. The sender however is real, a drug dealer in a small Kyuushuu town. Soon the Kyuushuu police are busy trying to trace his movements. When he turns up dead in the Seto Inland Sea, it looks like his suicide puts an end to the story; but his widow is not happy with this and asks an old friend, Inspector ONITSURA (鬼貫警部, Ayukawa's series character), to look into it.
Onitsura had been in love with the widow as a student and had lost out to the man who married her, a fellow student. In fact all the characters in the case were students with Onitsura: both victims, the drug dealer and also the first victim, a widely disliked far right militaristic zealot; and soon two suspects, a nervous artist and a tough minded industrialist. Onitsura soon turns up suspicious activity from a man dressed in blue, who must be the murderer; but it looks as though neither suspect could be the man.
What makes this mystery so good? I think that part of it is the single minded concentration on advancing the plot. In The Villa Lilac Murder Case the mystery remains unsolved until the end only by having incompetent detectives who never notice suspicious behaviour or ask questions every reader has thought of. In The Black Trunk both Onitsura and the local police detective who first investigates are competent. The concentration of the plot is notable. There are only two suspects that matter, and readers will probably quickly pick one of them. You could call this story "The One Red Herring". The characters are not exactly realistic; but they are interesting. Ayukawa allows himself the same freedom as modern drama to let his characters talk much more freely and directly than we would expect. This too helps the story move along briskly.
It must be admitted (as Ho-Ling's slightly less enthusiastic review notes) that there are stretches where the story just feels too complicated. You are asked to keep track of the separate movements of several people and pieces of luggage through the rail and boat systems of Japan from Tokyo to Kyushu over several days. There were certainly points in the story where I had trouble trying to remember what I was supposed to know about the earlier parts of the investigation. Certainly, even if I had made notes, I could never actually solve this in one go; but Ayukawa provides for us there too, I think. The solution proceeds by stages. We make one breakthrough, but find that we are left with a new problem. The reader can at least spot some of the (many) tricks, and as the solution proceeds we get a firmer grasp of the details, leaving us in a good position to solve the final puzzle if we want. Even for admirers of the Golden Age detective story, this is not a book for everyone; but for an admirer of Crofts it's well worth reading.