One of the best books I've read recently. Despite its really smart and complex plot, the book is easy and entertaining to read - even for a non-native speaker.
The parapsychological and historical background is extremely well researched and absolutely coherent.
The characters are interesting and seem to be taken out of real life. C.R. Martinez describes their characteristics in an amusing, ironic, yet affectionate way.
The surprising twists eventually make this book a really good and recommendable read.
Enjoy how step by step all the questionmarks in your mind turn into wow-effects.