Why does Ryland Grace, the hero and narrator of Project Hail Mary undertake such an unprecedented journey? Because the Earth’s own star, the Sun, is dying. Under attack from a mysterious energy-eating microscopic organism Ryland dubs Astrophage, the gradual dimming of the Sun spells the end of all life on Earth.

Unless something can be done… Ryland is recruited into the international effort to build a starship that can travel to Tau Ceti, a star that has been proven to be resistant to the Astrophage. The trip is to be one way, and Ryland, awakening from a medically induced coma and initially amnesiac, finds he is the only member of the three-person crew to survive.

Racing against a clock counting down to the death of the human race, Ryland puts Weir’s command of science and technology—and his ability to communicate it in clear and gripping language—to the highest imaginable test.