I'd give this a 3.5, really. It would have been a solid four, but for the final few chapters and a few other details.
Patricia Wrede's style was quick and lively, which was good, but the promising beginning was bogged down with far too many characters to keep track of towards the end (some of them entirely unnecessary at that) and an ending that has far too much exposition. I know that mystery stories usually do follow that trend of The Great Reveal, but somehow this one dragged and dragged until I basically skipped ahead. It almost felt like it was trying for a Heyer, in that coincidence brings everyone to the same place in the end for the final scene, but with a heavier hand, and with everyone talking each other to pieces.
Kim also played a smaller role than what one would have expected of the main character -- which I guess was understandable, considering her newness to the world of white collar crime, but she was overshadowed by nearly everyone in the end.
Still, I like Patricia Wrede, so I'm not against giving this book's sequel a try.