The In Crowd by Charlotte Vassell
I wish I had read The Other Half, the first in the Detective Inspector Caius Beauchamp series, before picking up The In Crowd. Not that The In Crowd doesn't work as a stand-alone, it does, but Caius is a full, rich character, the kind you appreciate more the more time you spend with them. His interactions with his staff, Matt Chung and Amy Noakes, are well done, too. I also feel like some of the other characters had parts in the first case that I missed.
This time around, Caius is working on two cases: the death of a woman who had been the girlfriend of a missing man suspected of stealing pension fund assets and the disappearance of a girl from boarding school years ago. The mysteries are complex and and the twists were incorporated well, and I liked how certain things pulled together. Honestly, though, it's Caius himself that would make me come back to the series....