Aaron investigates an explosion on Ascension, while Captain Denninger covers up its true cause. Elsewhere, Viondra suspects there is a traitor within her ranks of stewardesses after Councilman Rose becomes privy to inside information; something mysterious seems to be happening to young Christa Valis; and James Toback attempts to impress Nora by making a deal to get into Officers Training School.
In 1963, the U.S. government launched a covert space mission sending hundreds of men, women and children on a century-long voyage aboard the Ascension to populate a new world. Nearly 50 years into the journey, as they approach the point of no return, the mysterious cuddle of a young woman causes the ship's population to question the true nature of their mission.