Without spoilers, this book is two mysteries for the price of one, although I have to say I prefer one of them significantly over the other. It's a modern take on Agatha Christie and if I have one quibble, it's how much I dislike the modern female protagonist. She falls into every cliche of what an unmarried career woman should want, and being one myself, makes me want to scream. Please, male authors: stop this at once.
That said, I found it compelling to listen to, great performances, and reminds me why I love a great whodunit. Recommended, but with some reservations.