The Emperor of Evening Stars

I really enjoyed learning more about the events from the previous books from Des' POV as well as his past that was only offhandedly mentioned to Callie before. Des is a far more interesting character and this shed some light on some of the events that Callie's utter denseness prevented from being known in the previous books. Definitely wait until after you've read the first two books before reading as this goes from centuries before all the way up to the very same final scene of book 2. It seems like it will be a great segue into the next book, once that is released.