"The Murder of Mr. Wickham" by Claudia Gray

Well, I did read the whole book, which I kind of thought I wouldn't at one point.  And I'm glad I did, because the ending was reasonably satisfying.
The Murder of Mr. Wickham has a fun and clever premise: the characters from Jane Austen's six major novels are all related or know each other somehow.  George and Emma Knightley host a house party at Donwell Abbey to introduce Juliet Tilney, daughter of Emma's friends Henry and Catherine Tilney, to good society.  They invite Captain and Anne Wentwort...