Here's another series I've dipped into - Jo Nesbo's series about Norwegian detective Harry Hole. And I also like this series, of which I've only read The Redbreast and Nemesis, Books 3 and 4 in the series.
The Redbreast is a very intriguing book, cutting back and forth between modern Norway and World War II and the Norwegians who fought for Hitler. I hadn't realized there was a sizable contingent of Norwegians fighting for Hitler, having thought the recent shooting in Oslo to be a complete aberration of the Norwegian character. Perhaps not totally an aberration. Meanwhile, there's a parallel story involving officers within the police department, which is not resolved at the end of the book.
This was a complex plot to follow, made even more difficult because some of the names of the characters were very similar. If I ever fulfil my longtime ambition to write a book, I will ensure the characters' names are highly differentiated, to make it easier for readers. This is particularly relevant in a book that has been translated, where the names are unfamiliar to begin with.
I liked my second Nesbo book, Nemesis, even more. Harry eventually tracks down a bank robber, but nothing is straightforward in this plot as it twists and turns as Harry follows one hypothesis after another. Meanwhile, he girlfriend Rakel is in Russia fighting to retain custody of her child in corrupt Russian courts and that thread eventually weaves into the story too. Also, the story inside the police force continues although again it does not reach resolution,
This is another series I will keep reading. There are nine books translated into English, so I have lots to go. I didn't read Books 1 and 2, so I don't know what I missed there, but you should definitely read The Redbreast before Nemesis.