「この世のどんな出来事であっても、それが文章になってしまった時点で、それはフィクションでしょう。小説というものは、すべてフィクション。ノンフィクション小説、というのはそれだけで自己矛盾、自家撞着してしまうのではないかしら」
『QED ベイカー街の問題』
"Everything that occurs in this world becomes fiction the moment it is written down. Novels are always fiction. Non-fiction novels are by name alone self-contradicting oxymorons."
"QED The Problem of Baker Street"
I don't consider myself a true Holmesian (Sherlockian), but I am fairly familiar with many of the major Holmesian discussions. No idea where I pick these things up.
Since a year or so, I've been reading the manga series Q.E.D. Shoumei Shuuryou by Katou Motohiro semi-regularly. Some people might not be aware that there is also a completely unrelated mystery novel series titled QED, written by Takada Takafumi. I only read the first novel in the series a long time ago, so I am not very familiar with the series, but in general, this concept of this series is that it tackles both 'real-time' mysteries as well as historical mysteries, regarding historical events, famous persons or literature. The first novel for example had a famous Japanese poetry (waka) collection as its theme and in order to solve the 'real-time' mystery, it was also necessary to solve a mystery hidden within the ancient poems. The detective of this series is Kuwabara Takashi, nickname Tataru. He's an eccentric young pharmacist (specialized in Chinese medicine) who is quite knowledgeable about err, a lot, but especially literature. His assistant Nana is one of Tataru's very few college friends and while she too is a pharmacist, she works in a Western-style pharmacy.
The first two novels in this series were related to Japanese history, so the theme of the third novel might surprise readers, even if the title gives everything away: QED Baker Gai no Mondai ("QED The Problem of Baker Street", 2000) is of course about modern, British literature: Sherlock Holmes. One day, Nana runs into her college friend Yukiko, who turns out to be a Sherlockian. She's a member of the Baker Street Smokers, a Sherlockian club created by restaurant/club owner Hotta Soujirou. The Baker Street Smokers consists of four members and usually has small private meetings, but Yukiko explains they'll be holding a party on the sixth of January to celebrate the third anniversary of the Baker Street Smokers, as well as the hundredth anniversary since Sherlock Holmes returned to the land of the living in The Adventure of the Empty House. All members can invite people to come along, and the four regular members will even perform a little theatre play based on a Holmes story. Nana and Tataru are invited as Yukiko's guests, and Tataru even turns out to be a pretty dedicated Sherlockian, who can't wait to discuss a certain Sherlockian matter with other people. The party comes to an abrupt end when Sakimaki, one of the BSS members, is killed while getting dressed for the play. He was found lying on a table, stabbed in his stomach and holding a piece of paper with some incoherent writing on it. Given that few people at the party knew Sakimaki, suspicion naturally falls upon the remaining three BBS members, but it also appears Sakimaki's death may have to do with Tsukiji Natsuyo, a woman who was going to become a member of the BBS, but committed suicide some months earlier and who was doing research on a certain Sherlockian problem.
I am no expert on Japanese poetry, but I am familiar with Sherlock Holmes and Holmesian problems, so it was relatively easier to get into this novel than the first in the QED series. For those to whom the terms Holmesian/Sherlockian sound unfamiliar: it's a kind of game where people accept the Sherlock Holmes stories as written by Dr. Watson as having actually occured and discuss anomalies and other contradictions in the stories ('mistakes') with the premise that the events and characters mentioned in the stories are all real. For example mistakes in dates in the stories etc. are not 'mistakes by Sir Arthur Conan Doyle' but mistakes by Dr. Watson, or Dr. Watson had a reason to lie about the date, or there's some other in-universe reason. By the way, in Japanese, the preferred term is Sherlockian (like in the US), as opposed to Holmesian, which has my personal preference to be honest. Some might also remember the manga Sherlockian! I once discussed, which was actually quite informative.
Anyway, so QED Baker Gai no Mondai is about a murder committed among Holmesians, and meanwhile Tataru's also occupied with a Holmesian problem that bothers him: why was Sherlock Holmes acting so differently before and after the events of The Final Problem and The Adventure of the Empty House? While the novel does give brief explanations and summaries about all the relevant Holmes stories mentioned, it's clear that this novel is best enjoyed if the reader has some affinity/prior knowledge of Sherlock Holmes, or else you'll just be wondering why everyone is making such a big deal about a fictional character (blashpemy!). To be honest, the Holmesian mystery is far more interesting than the actual, real-time murder. In fact, the death count doesn't stay at one in this novel, but the other death isn't that interesting either, even if it involves a dying message with a Holmesian twist. But while the murders themselves are rather straightforward, in order to solve some parts of the mystery you need to have rather specific knowledge about medicine that isn't mentioned in the story until the denouement and basically, it's the 'anyone could've committed the murder, so let's focus on motive' type of story.
The motive behind the murders of course ties to a Holmesian problem, and I found that part far more interesting. Over the course of the novel, the reader will be presented various types of Holmesian problems of varying importance, but the most important is of course the one that's on Tataru's mind. The ground he treads with his theory is not particularly unknown, but it's fairly entertaining and well within the realms of what you'd expect of a Holmesian theory. And as you may expect from this series, aspects of Tataru's literary theory are also mirrored in the real murders, so it's necessary to solve the literary mystery in order to arrive at the motive, and even partially the modus operandi behind the actual deaths. I do like this linking idea, but in this particular case, it becomes a bit too artificial, with a lot of coincidence having to happen to create such a nicely mirrored situation in motive and actual murder.
I'm not even actually sure what to make of QED Baker Gai no Mondai. I definitely like the Holmesian background theme and it goes just deep enough to entertain me as a moderate Holmes lover, without feeling too detailed, but it's also very... vanilla-flavored in terms of the main murder mystery plot. The literary side of the mystery is far more interesting and while there are some interesting ideas like the dying message left by a Holmesian (can you guess what he did?), I thought the 'real' side of the mystery so plain and nondescript, I'm sure I'll have forgotten the details in a few months, while I am sure I will remember Tataru's Holmesian theory. QED Baker Gai no Mondai is a very safe read if you like the Holmesian theme, but on its own, it's hardly a stand-out mystery novel.
Original Japanese title(s): 高田崇史『QED ベイカー街の問題』