Imagine the universe as a forest patrolled by countless and nameless predators. In this forest, secrecy is survival – any civilization that reveals its location becomes prey. Earth has done so. Now the predators are coming. They will reach Earth across light-years in four centuries. But the Sophons, their extradimensional agents and saboteurs, are already here. Only the individual human mind remains immune to their influence. This is the motivation behind the Wallfacer Project, a final defense that grants four individuals nearly absolute power to devise secret strategies, hidden through deception and misdirection from both humans and aliens. Three of the Wallfacers are influential statesmen and scientists, but the fourth is a complete unknown. Luo Ji, a somewhat unambitious Chinese astronomer, is confused by his new status. All he knows is that he is the Wallfacer that Trisolaris wants dead.