The Old English Baron by Clara Reeve
There is a death and an inheritor of the estate of the deceased. Somebody comes in and decides there must have been wrong-doing. After a duel, it is determined that the inheritor ordered the killing of the deceased. The victor spares his life but orders penance. There is also a marriage involved with some of the parties. This is fairly fresh and modern for a book more than two-centuries old. It keeps grounded well in realistic situations.
