Combine lots of historical fact, enough fantasy to sweeten the plot and a modern crime story and you have the ingredients for a page turning book. The only problem is that the average reader (me) doesn't exactly know where the historical fact and fantasy start and stop. The process of sorting it out is made more difficult with the never ending switches in time.
I loved the book, but I would have liked the delineation between fact and fiction to have been a bit more clearly drawn.