
Crooked House by Agatha Christie
Crooked House is one of Christie's stand-alone mysteries. We have three generations of the Leonides family all living under the roof of the wealthy grandfather, Aristide. When Aristide is murdered, all the household comes under suspicion. His granddaughter Sophia tells our narrator and her fiancé, Charles Hayward, that they cannot marry until the killer is caught. Charles' father happens to be the Assistant Commissioner of Scotland Yard, so Charles investigates from the inside along with assigned detective, Chief Inspector Taverner.
The Leonides family members are an interesting, mostly unlikeable lot and any of them could have a motive - money, control. There are plenty of tensions and secrets. Charles makes a decent amateur sleuth and this one is more about uncovering family dynamics and tensions than concrete clues. The whodunnit is surprising, but makes total sense....