Finished the legendary Tokyo Zodiac Murders (1981) by Soji Shimada. Managed to guess the culprit and had strong hunch on the trick. I hear the next book in the series, Crooked House, is just as good. Luckily I bought that as well.
This short story collection is notable for being the first "bestseller" written in Modern Chinese.
Prior to 1919, the Chinese language displayed so-called "diglossia", where people spoke in various dialects of Modern Chinese but wrote in an extremely archaic version of the language called Classical Chinese. Similar to if you were to speak in Italian but write in Latin. The activists of the "May Fourth Movement" thought that the diglossia was an obstacle to the modernization of China, since not only was Classical Chinese difficult to learn for the peasants who made up most of the population (condemning them to illiteracy), but the requirement to use only the vocabulary found in the Confucian Classics made it difficult to invent new words to describe modern phenomena like "railroads" and "hydrogen".
The first attempts to write about serious topics in the vernacular must have obviously been stumbling and prone to ridicule. But a mere four years after the language reform, writer Lu Xun had found a style that allowed him to write scathing satires of late Qing/early Republic society while still being intelligible to a person who knows only Modern Chinese. It's clear that Lu is actually very educated and could have written fluently in Classical Chinese if he wanted to (one short story contains an entire paragraph in CC), but he deliberately writing in the vernacular because his political ideology says that literature should be available to everyone.
Despite the intention to be accessible, Lu's prose isn't entirely easy to someone who learned Chinese post-1949. He was more or less inventing Modern Written Chinese on the fly as he went along, presumably drawing on his own Zhejiang dialect as well as what he might have picked up of the dialects in Beijing and Shanghai, where some of the stories take place. Not all of Lu's vocabulary made into the Standard Chinese that the Communist Party created on the basis of Beijing Mandarin dialect in the 1950s, and as such some of his word choices seem awkward or even unintelligible to those educated in this variety. Notably, he uses the word bian 便 ("thus") where Standard Chinese would use jiu 就 ("so"), which gets very distracting when it's a word that appears in nearly every sentence.