I enjoyed both books so far. As one reviewer said, the first was probably a little better overall, but both have kept a good pace and keeping me entertained is all there is! I have been impressed with the background to the stories. The historical plagues, the volcanic winters and the 'human endogenous retrovirus' aspects have all given a lot more substance to these books than I have come to expect in my recent Kindle readings, so I am glad to give a positive review. I'm keenly waiting the next one.