Briefly: this is a disappointment. The whodunit aspect was a nice twist, but it's otherwise kind of bland and fairly two-dimensional.
Also, from the jacket blurb I expected the mysterious missing papers to be more exciting than what they were - this is not pirate gold or
Hollywood scandals or anything British. Much of the novel takes place in Los Angeles - there isn't really much back-and-forth, even, between London and LA, and -- well. As I said above.