2072. At the lunar farside radio observatory, an old-school radio broadcast is detected, similar to those broadcast on Earth in the 1940s, but in an unknown language, coming from an impossible source—Proxima Centauri. While the nations of Earth debate making first contact, they learn that the Proximans are facing an extinction-level disaster, forcing a decision: will Earth send a ship on a multiyear trip to render aid? 

Interstellar travel is not easy, and by traveling at the speeds required to arrive before disaster strikes at Proxima, humans will learn firsthand the time-dilating effects of Einstein’s Special Relativity and be forced to ponder ultimate questions: What does it mean to be human? What will it take to share the stars with another form of life? What if I return younger than my own children? The answers are far from academic, for they may determine the fate of not one, but two, civilizations.