I spent half a hour down a rabbit hole just because I couldn't remember if this was a library copy and Amazon deleted my review, which was witty and succinct and insightful but not spoilery, and not at all like the review of a very tired person, which I am.
Good book, lots of twists in the spaghetti and many of them unexpected.
Good for genre: suspense, romantic suspense, darkest London, amateur sleuth.
Library copy