E=Murder

aⁿ + bⁿ = cⁿ

(Fermat's last theorem)

I'm horrible at the exact sciences.. I imagine that if Q.E.D. Shoumei Shuuryou did its unique style of mystery telling not with mathematics or similar fields of science, but with literature or a field like that, I'd be a lot more enthusiastic.

After reading a couple of volumes of Katou Motohiro's Q.E.D. Shoumei Shuuryou series and the sequel series Q.E.D. Shoumei Shuuryou iff the last year, I realized that I don't have any interest in reading all the adventures of the brilliant, MIT-graduated prodigy Touma Sou and his classmate Kana. There are definitely some interesting stories in this series, especially when the stories involve mathematics and other special fields of interest of author Katou himself, but few stories are truly memorable as mystery stories, so I have decided I am just going to pick my stories now, instead of going through all fifty volumes of the original series, and another dozen or so for the still running sequel iff, as that's just too pricey. Fortunately for me, special anthology volumes were released earlier this year, with the three mystery authors Tanaka Yoshiki, Tsuji Masaki and Arisugawa Alice each editing their own volume. These volumes seemed interesting enough, and when I asked for story recommendations a while back, I noticed a number of the recommendations I got happened to have been selected for Q.E.D. Shoumei Shuuryou The Best - Arisugawa Alice Selection (2019), which made it the most logical next step in my reading of this series.

The volume starts with Jacob's Ladder though, which I already reviewed earlier, so I'll be skipping that story. The second story is Infinite Moon (originally in volume 20) and starts with the arrival of an email from Touma's Chinese friend Hu. Which is a bit strange, Hu was presumed dead, due to a heart disease he had been suffering of his whole life. The email to Touma also prompts a visit by the Shanghai Police, who tell Touma that Hu is known to them as a member of Xi Xing She, a crime syndicate in Shanghai led by four men: the two Liang brothers and the two friends Huang and Wu. While the gang was basically divided in two factions (the Liang brothers, and the two friends), the four bosses carefully kept everything in balance, until three weeks ago, when Huang was fished dead out of the river. While the police had trouble getting information out of the lower-ranked members of the Xi Xing She, it appeared Huang's murder was retaliation by the younger Liang, as Huang had killed the elder Liang brother earlier. The police hope that Touma's friend Hu can tell them more about the power struggle going on, but time is ticking as the remaining Xi Xing She bosses kill each other off, while Touma has to figure out Hu's mysterious message: Come to ϕ. I have read several stories with a series of murders, where the murderer becomes the next victim and then the second murderer becomes the next victim etc., so Infinite Moon was not really surprising to me. I like how Katou links the story with mathematical theories in infinity and 0, but the core mystery plot is not really surprising: a lot of pages are used to simply explain the basic setting, but after that, you don't really need much explanation/clue-hunting to figure out what's going on.

The Kurogane Manor Murder Case (volume 36) reunites Touma with Karasuma Renji, a cocky assistant-professor in Physics who has a soft spot for Touma. Karasuma is a "person of interest" to the police in the investigation into the suspicious death (apparent suicide) of Professor Kurogane of K University in Kyoto. It was Kurogane who had sent Karasuma away from K University all the way to A University and even then, Kurogane kept the brilliant Karasuma shackled: he arranged so Karasuma's research at A University would become a joint project with K University under the supervision of Kurogane's own pupil Shida, which would mean Karasuma's name would end up below both Shida and Kurogane's names on his own research paper when published. Kurogane however was found hanging in his study in his manor one day ago, precisely when Karasuma returned to Kyoto. Kurogane had no reason to commit suicide, but murder also seems impossible as there were no footprints in the snow around Kurogane's study, nor did the help see anyone come or leave the study that day. The police can't really pin anything on Karasuma, but at the wake in Kurogane's manor, a more obvious murder happens: an arrow is shot right in Shida's neck during the night, but due to the long, covered galleries of the traditional Japanese house, none of the suspects could have shot Shida with a bow and arrow from their respective positions, due to the distance and most importantly the low ceilings of the hallways.

The death of Kurogane in his study itself is rather simple, though I do like how it makes clever use of the way a traditional Japanese manor is built (Katou studied Architecture in college). One important hint to the whereabouts of the culprit at this crime site is rather brilliant though, being a reference to Zeno's arrow paradox, though it does expect the reader to guess a certain's character behavior for it to work. Shida's murder is... original, but kinda hard to swallow. The way the building is used to create an impossible situation is great: it makes references to a special archery competition that challenged people to hit a target from one end of a covered gallery to another, the low ceiling making it difficult to shoot an arrow far enough (as an arrow needs to get high to be able to fly further). Karasuma for example had a clean shot on the victim from his position for example, but he'd need to be the strongest person around to have made that shot straight across the gallery. The trick behind the murder however requires you to kinda roll with it: it's original and it definitely works better due to the visual format of the story, but it kinda expects you to a) to know that's possible in the first place and b) that it would actually succeed in one try (even if with some practice), for the arrow was just as likely to hit a non-vital part or simply miss the target. In fact, an acquaintance with experience with archery basically rolled her eyes in disbelief when she saw the solution.

Locked Room No. 4 (volume 40) brings Touma, Kana and Himeko as members of the Sakisaka High School Mystery Club to the classic mystery setting: a mansion on a remote island. Sparrow Tours is a small tour operator/planner specialized in unique experiences, and now they're planning to do a mystery tour on this island, where the participants have to solve a mystery (locked room murders) during their stay. The story for this tour is written by the mystery author Yoimiya Sodehara, and the three kids have come along to act as a test panel. Another 'outsider' is Komaki, the head of Accounting of the parent company World Tours, who says Sparrow Tours' expenses are way too much and that he needs to take care of it right away. Once the group arrives on the island, Komaki goes off on his own, while Toum, Kana and Himeko are presented with the three locked room murder situations of the tour (the victims being played by the various employees of Sparrow Tours who have come along). The three kids quickly solve the three locked rooms (to the frustration to the author Yoimiya), but when they go to the dining room to rest, they find it locked. When they unlock it, they discover the body of Komaki sitting at the dining table, with lit candles illuminating the knife in his chest. With the door locked and the window looking down a cliff, it seems the gang is being presented a fourth, unplanned locked room in their tour. The first three locked rooms are pretty much child's play, and the gang manages to solve them almost instantly. The fourth, main locked room is of course more interesting: it's not super complex, but makes clever use of all that has presented before (like always Q.E.D. stories usually take a long time to set the story up). It's pretty obvious who the murderer is once you see through the main piece of misdirection, but I think this was a nicely plotted tale within the usual 100 pages.

In Question! (volume 44), Touma, Kana and Loki arrive at a mountain lodge house after Touma receives a mysterious letter that says "Question!", featuring Fermat's theorem inside. Included were also directions to the mountain lodge, and curious as to the meaning of this letter, the trio decide to go there. There they find two other groups, who happen to know each other from the local family court: both an elderly couple and a younger couple with a daughter who are living seperately now and busy working out a divorce. At first, the two groups figured this was some kind of last effort by the family court to have the two couples talk things over, but Touma's presence obviously proves that idea wrong. All of them have received the same mysterious letter, though with different riddles. The story unfolds as a kind of treasure hunt, with the solution of each riddle pointing towards another riddle and all coming back to Touma's Fermat's theorem. Don't expect to do much mystery solving yourself as the reader, as that's pretty much impossible and a lot of the story is also devoted to Touma's lecture on Fermat's theorem. It's pretty easy to guess what the story is really about though. Detective Conan also often features stories like these, but I find them more enjoyable there, as they work better as standalone mystery stories with a riddle that can be solved by the reader themselves, whereas even with knowledge on Fermat etc., Question! is mostly just guessing.

Q.E.D. Shoumei Shuuryou The Best - Arisugawa Alice Selection is on its own a fairly entertaining volume. Not a big fan of the opening and ending story of this selection, but the middle part is good Q.E.D. stuff and include some of my favorite stories I have read until now of this series. Arisugawa also obviously selected stories that showcase Katou's interest in mathematics and other academic fields: those topics are often mentioned in the Q.E.D. series, but they play an especially important thematic role in most of the stories included in this volume. I might also pick up one of the other The Best volumes in the future, as I think this approach (picking my stories to read) is probably the best way to enjoy this series for me.

Original Japanese title(s): 加藤元浩（原） 有栖川有栖（編）『Q.E.D. -証明終了- The Best 有栖川有栖Selection』