I realised I never put down my thoughts on this one, which is a shame, because I thought it was really, really excellent. I wolved this down within a few days and I know for certain I will want to pick it up again and re-read it in the future. The book's greatest strength has to be its convincing characterisations, from the main characters all the way down to the supporting cast. Every character reads like a fully fleshed-out human being, complete with flaws and vices and secrets that impact their actions and - ultimately - the larger narrative by raising the investigator's (and the reader's) suspicions and creating numerous false leads.
Because of that, the narrative surrounding the investigation itself is full of sweet, sweet suspense. Some of the chapters read more like a thriller than a historical crime novel.
But what really stood out to me about this novel, far more than the main plot, far more than the main character starting to question his morals (and his sexuality) more and more with every page, is the time the novel takes to show us how the criminal investigation that constitutes the main plots affects the lives of all the little people caught up in its margins, from characters missing trains to characters having their entire lives upended by their extra-marital affairs being exposed. After a few chapters in, I became genuinely concerned about every new minor character who was introduced, because I feared the effect the investigation might have on them.
If you're the kind of person who gets annoyed at blockbusters laying waste to entire city blocks in cool action sequences because "hey, that's somebody's home!", you need to read this book, because it's full of scenes that look back at the little people after they've been swept-up by the main plot and looks at them with sympathy.
The only reason I can't fully recommend this book to absolutely everybody without reservations is that, in the case of one particular character, the book falls back on what I consider very racially-charged stereotypes that didn't sit quite right with me. The book features multiple Jewish characters from different sections of society, so I don't suspect any malice behind the way this one particular Jewish character is written, but the fact remains that there is one rather important Jewish character in this novel (not a main character but definitely not a minor character either), who is presented as porn-obsessed, sex-obsessed and super-rich, who ends up seducing and carrying on an affair with a married white woman. This character is NOT a villain or portrayed as a criminal or anything like that, but the connection to that old stereotype of the rich, unsavory Jewish man going after the white woman is certainly there and I feel like this is something people might wanna know about before they dive into this thriller.
Another part of the book that might not sit well with readers is a brief mentions of teenaged characters having sex and it's never made clear how consensual that relationship was. Given how common sexual abuse is, I thought I'd mention this as well, just in case this is something you don't feel like reading about.