Second book in the series. It starts with the introduction of the Wallfacers, a small number of people assigned to invent novel solutions to the problem of the Trisolarian invasion coming in a few hundred years, which seems bound to succeed thanks to the block on science advancement caused by the sophons launched in book 1. These heroes are required to do all their thinking inside their heads, the one place the sophons cannot penetrate, and they are given essentially unlimited resources to do their work. The main focus is on Luo Ji, who has studied cosmic sociology, based on two axions: 1) Survival is the primary need of any civilization, and 2) Civilizations constantly grow and expand but the total matter in the universe stays constant. These are seeded to him by none other than an old Ye Wenjie from the last book, and apparently his publishing causes him to be named a Wallfacer. He spends much of the book in hedonistic pleasure, though, before launching an odd "spell" at another star nearby and then going into hibernation, finally forced by the authorities to stop living in isolated splendor with his dream woman and child and start working. We read about the other Wallfacers too, as well as the Wall breakers sent by collaborators to expose their plans.

There is a time jump of almost 200 years, and we see a wondrous advance in civilization as the first probe of the Trisolarians approaches the solar system. The space fleet goes out to intercept, with predictably dire consequences. It's looking very bad for humanity, until the tail end of the book.

Luo's plan is a well-hidden mystery until the Big Reveal, and there is also some interesting stuff happening in the fleet and with the author's conception of how Humanity might react to near-certain destruction over time. A sci fi podcast I enjoy opined that these books have a great concept, but characters that are paper thin. I would add that the writing style (or the translation to English- I guess we can forgive the writing since it's not in its original language) isn't great. But the concept is cool, and the reveal is good. Worth the read. ( )

The continuation of The Three-Body problem.

Like the first, I enjoyed it a lot. It's not perfect. Sometimes the Trisolarans' stupidity is painful, and the humans have more than their share too, and it stretches credulity that being so technologically advanced the Trisolarian fleet travels so slowly and that they are so ineffective in some ways. But for me that is easy to forgive, because the style is so fresh and different, and because of the high density of ideas and the grandiosity of the story. Unlike the Three-Body Problem, this second book would be a good stopping point, because it finishes the story, but I'll be reading the last book, because I'm enjoying this.

Note after reading the third book: Even though story-wise this second book would be a good ending point, do yourself a favor and read the third book: It's amazing. ( )

Thoroughly enjoyable. A very unusual premise, utterly intriguing and fascinating, I shall definitely have to finish the trilogy. As you might expect from such a different culture, the pacing and the language can be a little strange at times, but that is also a large part of the charm. I'm glad I came across this, Netflix is useful for something! ( )

everyone who told me this was the best book of the trilogy owes me $500, that's one dollar for each page of this that i managed to read, somehow, despite being for the most part totally boring. at best there are interesting ideas that are drawn to a weak conclusion, and/or it was so long since the ideas were introduced that their resolution lacked any emotional weight entirely. there were some passages that really sucked me in (most of the stuff with zhang beihai. i liked his story) and then there was most of this book, which just dragged and dragged and dragged. also, the three body problem was filled with fascinating messy female characters; the dark forest suffers from soft misogyny disease, in that the women are mostly in the background and the two main ones follow similar narrative beats, especially in the first half of the book. which would not have bothered me as much if the first book hadn't been so damn good. i will probably still read the third book someday though just because i'm like where the hell can it possibly go from here. also because it's back to the first translator and i can't discount that this was the key problem. ( )

So I read the first book, and I thought it was very good. Then I read this one and suddenly I felt like compared to this the first one was nothing. It just blew my mind, repeatedly. ( )