The Dark Forest is the 2nd book in The Three-Body Problem Series.

Imagine the universe as a forest, patrolled by numberless and nameless predators. In this forest, stealth is survival - any civilisation that reveals its location is prey.

Earth has. Now the predators are coming.

Crossing light years, they will reach Earth in four centuries' time. But the sophons, their extra-dimensional agents and saboteurs, are already here. Only the individual human mind remains immune to their influence. 

This is the motivation for the Wallfacer Project, a daring plan that grants four men enormous resources to design secret strategies hidden through deceit and misdirection from Earth and Trisolaris alike. Three of the Wallfacers are influential statesmen and scientists but the fourth is a total unknown. Luo Ji, an unambitious Chinese astronomer and sociologist, is baffled by his new status. All he knows is that he's the one Wallfacer that Trisolaris wants dead.

A milestone in Chinese science fiction. - New York Times

The best kind of science fiction. - Kim Stanley Robinson 

A breakthrough book... a unique blend of scientific and philosophical speculation, conspiracy theory and cosmology. - George R.R. Martin