Once again, Peter May puts together a strong mystery while illuminating key cultural differences between China and the USA. He also paints a fascinating picture of how China has "opened" up to a capitalist economy while maintaining its authoritarian communist political structure. The relationship between quixotic Chinese cop Li Yan and cranky but brilliant forensic pathologist Margaret Campbell continues to provide interest, although their utter lack of communication at times needs to be better explained. I also liked the touch of having each of them dealing with a difficult parent in the book as they prepare for the wedding.
If there is a flaw in these books it is the author's need to tie up all the loose ends by killing off all the bad guys at the end. There is a killing in just the last few pages that seems tacked on and confusing in light of the dead man's character. I've read four of these thrillers, and there's always a wild, overly violent series of killings at the end, with little explanation of what happened to our main characters. I suppose this is designed to keep us reading the next one, but it leaves you feeling unsettled at the very end, and seems overly sensationalized.
I also think the science involved is very far out, futuristic, but I suppose it's possible.
Overall, the two main characters are very strong, but we could use more scenes with them together to develop their relationship for the reader, and the ending is a little confusing. But the cultural differences are fascinating and the picture of 21st century Beijing (with the necessary historical background to help us follow it) are worth these other flaws.