'The Dark Forest' by Liu Cixin

The Dark Forest is a mind-expanding thrill ride of interstellar proportions. This epic sequel to The Three Body Problem brings readers to unimaginable cosmic and futuristic settings. The tension is always high, given the stakes. As we learned in The Three Body Problem, there is an alien fleet headed towards Earth, and we never forget this chilling fact as it casts its shadow over the story from the very first page. Whether it is a United Nations conference discussing humanity's space defence program, or an observatory measuring the fine movements of the slowly approaching alien fleet, the scope and tone of Liu's epic tome is unique and thought provoking. I could not help wondering what indeed would happen on our world given this scenario. I feel that Liu's presentation of this story is incredibly realistic given human nature and our relationship with the great unknown of outer space. How would we react to the discovery of an alien civilization? How would this shape geopolitics, our collective psychology and our family planning? These are all questions that Liu address beautifully in The Dark Forest.

From a star system quite unlike our own, Liu's alien civilization (called Trisolaris) is different from humanity in many ways. Perhaps the most important difference is that they have no ability to conceal their thoughts. The physics of their minds is such that all their thoughts are 'out in the open'. They know exactly what one another are thinking about at all times. There is no way for them to deceive or lie. Humanity has one weapon against Trisolaris: that we are able to conceal our thoughts. What is often a negative and unsavoury element of human nature is in this book used as our last defence.

We learned in The Three Body Problem that Trisolaris sent sophons to Earth. These microscope particles are an advanced technology that allow the Trisolarans to monitor all human activity. The sophons are a ubiquitous invasive artificial intelligence that even have the ability to block human technological progress beyond a certain degree of sophistication. Knowing that human technology seems to develop exponentially, the Trisolarans worried that by the time their fleet arrived at Earth, humanity's space defence could potentially grow to a formidable level. Given Trisolaran spaceship technology, the fleet would take more than 400 years to arrive at Earth. This is one of the main reasons why the sophons were sent out first. They can blast the sophons towards Earth at much greater speeds, and the sophons could retard human technological growth to some degree. Even human conversation is being monitored! This is why the United Nations develops the 'Wallfacer Project', which nominates four individuals to work independently on a plan to defeat Trisolaris. The wallfacers are given access to all the resources that they need, and are never asked questions about their plans. The whole idea is that the wallfacers must deceive in order to develop a successful strategy without the sophons finding out about it! The main character, Luo Ji, is one of the wallfacers and thus this is all the set up to our story. I find it compelling that the theme of using lies to humanity's advantage is so emphasized by Liu Cixin. I believe that this is a version of the classic literary theme: use the darkness within yourself to create light in the world.

I did not have a lot of experience with the science-fiction genre before I started reading this series, but I can now say that I am a huge sci-fi nerd. Liu is clearly a deep and intelligent thinker and he leaves few details unexplained. Being less scientifically literate, there were times where I had trouble following exactly what he was describing. He outlines endless details from the construction of space warcraft, to the optics of telescope technology, or the futuristic advances of our species. Do not fear, though! Even the scientific illiterate like myself can still enjoy this book because it is not pure scientific jargon. There are also real emotional moments, and this is what makes the book so enjoyable. You sometimes need to slog through the hard science to get to the geopolitics or the human emotion that really makes you invested, but when you get there it certainly does not disappoint.

There is also some impressive world-building in this book. Since the Trisolaran fleet will not arrive for 400 years, Liu's epic spans a large amount of time. We are eventually transported 200 years into the future, which gives Liu the ability to create a futuristic world. Humanity is displayed as technologically superior in ways that are surprising. There are definitely some major aspects of this futuristic vision that I did not expect and that I had not ever even imagined. I do not want to spoil anything, so I will leave this futuristic world for you to discover if you choose to read.

Apart from all my praise, I have one heavy criticism: there is a lack of character development. One character in particular, Zhuang Yan, is heavily underdeveloped. She appears in the story out of thin air, and is never given enough attention. She is an idyllic woman who conveniently falls in love with the protagonist despite having no believable reason for even liking him. I find this insulting. Nevertheless, accepting the fact that she falls for this unimpressive man, I would have been interested in getting her perspective on the story's plot. She is in such close proximity to all the events that it is a huge shame that we never get to hear her thoughts. It is a massive failure and I believe that Zhuang Yan is being used more as a prop than a character.

As damning as that criticism may be, I must say that I wholeheartedly approve of at least 80% of this book. I would recommend it to anyone who wants to fly into space and experience the vulnerability of humans in an unknowable universe. There is so much in this book that I have not even included a description of what "the dark forest" is! For anyone interested in philosophy, the theory of the dark forest is an amazing twist placed at the end of the book in a highly rewarding and cathartic way. If you can make it through the cavernous pages of science and discovery, the highly original ending of The Dark Forest will surely have you raving about the book to your friends, as I did, and staring up at the stars at night asking yourself what is up there, and is it even worth discovering.