The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life—another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod—there’s only one thing he can do: open fire and eliminate them. In this forest, hell is other people. An eternal threat that any life that exposes its own existence will be swiftly wiped out. This is the picture of cosmic civilization. It’s the explanation for the Fermi Paradox.

This is the second book of the “Remembrance of Earth’s Past” trilogy by Liu Cixin. The book continues the story in the Three-Body Problem and explores the decisions humanity makes finding that an alien civilization heads for Earth, bent on destruction, in 400 years.

The story is followed through the eyes of Luo Ji, a lackadaisical astronomer and sociologist, who is named one of the four Wallfacers, the humanity project to hide its intentions from the Tri-solarian aliens. The anchor of the book remains Luo Ji’s quiet protector, the detective and policeman Shi Qiang.

Years and generations pass and humanity oscillates from the height of optimism and arrogant self-confidence to the depths of despair, when its fleet is easily taken out by a single alien droplet.

The questions addressed and the hard science put into the plot makes the novel a fascinating read. Weaker than the first book, this volume gives less space to the aliens and more to the personal story of Luo Ji.

The book is not a hero’s story, struggling for humanity, but of an unambitious fellow put, sometimes inexplicably, in positions of decision with grave effects for humankind. The book has no real protagonist, as Luo Ji is not sufficiently explored to understand all his decisions.

The alien motivations and the world building are beautifully exposed and are logically impeccable, while humanity’s response is lackluster, even disappointing. Few raise to the task, including our main personage.

The volume is of excellent writing quality and the story is well followed and expanded from the first book. A less exhilarating experience than The Three-Body problem, but, nonetheless, a great book to read.