The Trisolarian fleet has left their house world and will get to four centuries’ time. But the Sophons and their extra-dimensional emissaries already are here. This is the motivation for the Wallfacer Task, a last-ditch defence that grants four individuals nearly absolute capacity to style secret strategies, hidden through deceit and misdirection. Luo Ji, an unambitious Chinese language astronomer, is certainly baffled by his new position. All he understands can be that he’s the main one Wallfacer that Trisolaris wants dead.