The Unfinished Clue by Georgette Heyer

It should have been a lovely English country-house weekend. But the unfortunate guest-list is enough to exasperate a saint, and irascible General Sir Arthur Billington-Smith was nobody's idea of the perfect host. In fact he was absolutely frightful. He bullied his wife, Fay, grumped at his guests, refused gleefully to help his financially stricken indigent nephew, and positively blew his stack when his wayward son, Geoffrey, took up with a nightclub dancer, Lola de Silva, who was definitely N.Q.O.C. (Not Quite Our Class.) Sir Arthur is an abusive wretch hated by everyone from his disinherited son to his wife's stoic would-be lover. But a houseful of people he loathes isn't his worst problem…

Is it any wonder that one fine, bright, English June morning Sir Arthur quite literally became a bloody bore when he was firmly stabbed in the back with a pretty little Chinese dagger? When he is found death, no one is particularly grieved, least of all his family, -- and no one has an alibi. The unhappy guests find themselves under the scrutiny of Scotland Yard's cool-headed Inspector Harding from London, who has solved tough cases before -- but this time, the talented young inspector discovers much more than he's bargained for.