Payment In Blood (Inspector Lynley Mysteries)
I saw this first on TV as an adaptation. It's an interesting story that interweaves jealousy, betrayal and suspicion. Lynley has a problem in this case that it pivots around the woman he loves, Lady Helen Clyde. Havers can see that he is biased in this case and wants to save him from himself and it's all turning into a huge mess of betrayal, intrigue and a past that people are willing to kill for.
There were times when it lagged a bit but I really did want to know who did it.