Cixin Liu’s The Dark Forest (Vol II) indeed is dark and is best understood if The Three-Body Problem (Vol I) is read first. This sequel allows the reader to look at the strategies and attitudes of earth inhabitants when astronomers confirm aliens from Trisolaris are in route and will arrive in a few hundred years. Nations work together for the defense of earth, some with great confidence, but some groups believe all hope is lost (defeatists) and others that a remnant must escape (escapists) into space.
As was seen in Vol. I, the Trisolarians somehow have access to most human technology (sophons?), but lately it was discovered secrets could be hidden in the human mind. In some early and infrequent communications, the Trisolarians expressed confusion that humans needed different words for thought and speech because with them all thought was public and a principal means of communication. Could this be important for earth defense or in negotiations?
Towards the end of this volume, an advance probe from the Trisolarian fleet enters our solar system and is found to be of beautiful raindrop shape and mirror-like exterior. In a most stressful attempt to capture and examine the probe, one described it as a tear from the Mother of God and all approached it with much apprehension.