"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."--