1963年,在冷战太空竞赛中,美国政府秘密发射了升天号(Ascension)太空飞船,携带着一百名男女老少,完成一项世纪航行:寻找新世界,保存人类生命火种。这段旅程期初一切顺利,但很快就陷入了巨大的危机之……A young woman's murder causes the subjects of a century-long mission to populate a new world to question the true nature of the project as they approach the point of no return.