In some ways, this is perhaps the weakest book of the trilogy, in part because the scope has expanded to such an extent to include not just the Trisolarans, but also space species of other origins, the time span of the story stretches to centuries-long, and the speculative aspect of science outside of relativity and quantum mechanics is pushed so far beyond what seems possible, that the story verges on the level of absurdity on par with some episodes of Doctor Who. Though the inevitable end is suitably moving and devastating, and its flaws notwithstanding, the trilogy is one of the most imaginativea and mind-blowing science fiction I have read.