A lonely astronaut must save Earth from catastrophe in this incredible new scientifically grounded thriller by the number one New York Times bestselling author of "The Martian."

Ryland Grace is the sole survivor of a desperate final mission—and if he fails, humanity and the Earth itself will perish.

But at the moment, he doesn't know that. He can't even remember his own name, let alone the nature of his mission or how he is supposed to accomplish it.

All he knows is that he has been asleep for a very long time. And he has just been awakened to find that he is millions of miles from home, with nothing but two corpses for company.

With his dead crewmates and his hazy returning memories, he realizes that an impossible task awaits him. Alone on this tiny ship, cobbled together by every government and space agency on the planet and hurled into the depths of space, it is up to him to defeat a threat to the survival of our species.

And thanks to an unexpected ally, he might just have a chance.

Part scientific puzzle, part breathtaking interstellar journey, "Project Hail Mary" is a tale of discovery, speculation, and survival that rivals "The Martian"—while taking us to places we never dared to dream of.