So I didn't know anything about the actual story of this book when I got it, so simply based on the title and the cover, I was expecting this to be something set in the Middle Ages/Renaissance exploring the theme of death. It was nothing like that.
The book starts with the arrival of Shinohara Tsunajirou, Monoda Yoshihara and Mashime Kyouka at the Mishima residence, located in the forest surrounding Lake Ensui in the mountains near Matsumoto City in Nagano Prefecture. The two-storey building belongs to Professor Mishima Souichirou, or to be exact, his widow: the professor had started construction on his home, but he died in an accident on the lake. His widow, Otono, however had the project continued, with a large part of the house dedicated to her husband's accomplishments and his hobbies. Some time has passed since the professor's funeral, and Otono has invited a few old friends of her husband to stay a few nights at the lake, including the aforementioned trio, who were students of the professor. Tsunajirou and Kyouoka often visited the professor and his wife and knew them privately, so they are a bit surprised Yoshihara was also invited, and it's also a bit awkward: Yoshihara was never close to the professor nor his wife, and Yoshihara and Kyouka also used to date when in university. They broke up and now Tsunajirou and Kyouka are now an engaged couple. When they arrive at the house, they learn their host is not present. The physician Miyabi Daisuke, a Mishima family friend who knows Tsunajirou and Kyouka as well, arrived earlier, and explains he found a package hanging from the door knob, which included the keys to the house, as well as a letter signed by Otono, who explains she had an accident herself and can't freely move. Because it happened only a few days ago and she knew all her guests had already made arrangements, she asks their guests to entertain themselves despite her absence: food supplies have been prepared, so they can enjoy a few days off at the lake. Everybody finds this a bit weird, including Annosawa Ikuo, a budding mystery novelist who's a patient of the doctor (he was brought for some social contact). A late arrival is Takao Hiroshi, a salesman for a medical company who was also invited.
As they discuss their current situation, they note that the note doesn't actually sound like it was written by Otono, and Kyouka seems eager to leave, saying they should pay the widow a visit in the hospital, but they decide to stay for at least one night, especially as it starts to snow heavily. They explore the house a bit to admire not only the late professor's collection of insect specimens, but also his collection of torture devices, including the giant guillotine standing outside the entrance of the house. The following day however, a horrible discovery is made: Kyouka is found dead in the garden, with her face having been hit with immense force. It's obvious not an accident, as the object that inflicted the damage is nowhere to be found. Meanwhile,Monoda Yoshihara can also not be found, so the others start looking for him: they find his body floating in the lake, having first been strangled and then thrown into the lake for him to drown. The police is informed, but the road conditions due to the weather prevent them from coming at once. As the survivors await the police however, more deaths occur: a poisoning, a man being split in half with the guillotine... And when the police finally arrive... they find all six guests in the house have died, with the last one apparently having committed suicide.
It's the sister of the last person to live who visits Kumode, who runs a construction consultancy agency which double-acts as a detective agency, after earlier success in detection by Kumode. The sister naturally can't stand her brother being painted as a cold-blooded killer who killed five people and then himself, so she wants Kumode to investigate the case, which is done by an investigation of the crime scene itself (the Mishima residence), as well as the inspection of two diaries: one by the mystery author Annosawa and the other by the supposed killer: these were the last two men surviving and both men claim they were not the horrible serial killer in their respective notes. Can Kumode figure out what really happened at the lake?
Shi no Meidai follows the familiar tropes fairly faithfully, and some characters even point out how everything feels a bit fishy, from their host not appearing herself and the selection of guests being weird. Which is why it does feel a bit strange the characters don't decide to leave at once: they're apparently somewhat savvy enough to realize not all is right, but they still stay, and that's a thing that continues throughout this book: the characters really feeling like characters in a detective novel, doing the exact things needed to get the plot going, but not really fully explaining why those characters would ever want to do that.
The same holds for the core mystery plot: there are some cool ideas that are at play here, some honestly really memorable (and gruesome!), but many of the ideas used here are quite forced, especially if you consider them having all happened in the same story! Like, the murder of Kyouka is actually pretty interesting as an idea: it's actually an impossible crime, as the garden was covered in snow and yet only Kyouka's own footprints could be found in the snow, despite being hit from nearby with an object. I can easily imagine this part being a short story on its own as it has a memorable trick, but then you also remember the murders on the doctor and Annosawa also happened in their specific manners, and you start rolling your eyes as that's a bit too much luck/coincidence that is happening in one sequence. The murders on the doctor and Annosawa again would have been great core ideas in their own story (it's actually really good while being incredibly silly at the same time, and I love it for that), but it loses its impact here because it just becomes one small cog in a much larger machine. A far more fantastical machine than the realistic mechanism we saw in Kenchiku Shizai too. The way the murderer planned for all of this is almost farcical, as it relies on one coincidence or lucky turn after another, so taking this story in as.... one story feels a bit difficult. There are really good individual ideas, but they didn't need to be taken all together, especially as it works towards a conclusion that only strengthens this sense of forced coindence. I think if the book had been written differently, this theme could easily have worked, but the book is still told in a fairly straightforward manner that doesn't really dwell on the thematic consequences of its events, so you are never sure whether the author actually realized his book borders on a parody.
The book actually opens with a Challenge to the Reader, containing 5 'pointers' that act as a kind of tease of things to come. I think the book's fair enough to warrant a Challenge, though I'm not sure whether it works best in this position of the book (why not just before the soluton?).
Shi no Meidai is a book I think some of the parts are better than their sum, with some good mystery ideas and tricks, that however become a bit deluded when taken all together, because all of that happening in the span of like two days feels a bit too much, especially as part of a plan by the killer. It's also completely different in terms of atmosphere from Kenchiku Shizai, despite being the same series, which might be a good or bad thing depending on what your thoughts on that book was, or vice-versa. I think that the individual elements of Shi no Meidai are far more memorable to me than Kenchiku Shizai, but I found the latter a better novel overall.
