Unnatural Death by Dorothy L. Sayers

This is definitely my favourite so far of the Peter Wimsey mysteries (and I loved the previous two) because the story is inventive, elegant, exciting, and the book has a really masterful combination of humour, sudden grim and tragic events, and moral dilemmas. Lord Peter is exceptionally hilarious with his particular brand of humour, almost trivially quoting and parodying famous writers and sort of play-acting his way through his own role in the story. The play of class difference between him and Inspector Parker is also especially funny in this novel, with Parker the efficient, disciplined policeman, and Wimsey always asleep or taking baths at ridiculous times or going off to bid on rare editions at Christie's. I just find Lord Peter so ridiculously charming and silly, and I loved the part where he sets Parker up to think that he's taking him to visit his mistress (again, taking advantage of Parker's assumption that the upper-class Peter would be 'amoral' in sexual matters), while actually taking him to be introduced to a fantastically energetic middle-aged spinster to whom Peter has 'outsourced' some of his detecting work. On the other hand, there's a very dark current running through the book; the original crime that was committed was a woman killing off her already-dying relation to get her money before a certain law is passed, and would never have been found out if Lord Peter hadn't started investigating it. Through doing so, he pushes the murderess into committing several other murders, which she certainly would not have done otherwise. At the end of the book, it turns out that Peter in fact precipitated all the latter and brutal crimes. Interestingly, there's a whole series of lesbian characters, who are portrayed in an ambiguous way; the murderess is a lesbian who 'seduces' another girl into a same-sex relationship, and it's implied that the other girl ought to have found a nice husband and settled down (instead of which she wound up getting killed). But then there's also a lesbian couple who live together happily until the death of one of them, breeding horses and beloved by everyone in the community. It was a really great and satisfying read, and super fun and engaging.