Ellen Ripley finally returns to Earth, only to discover that LV-426 — where the crew of the Nostromo first came into contact with the deadly xenomorphs — has been renamed Acheron. Protected by Colonial Marines, the colonists seek to terraform the storm-swept planet against all the odds. But in the face of brutal living conditions and the daily struggles of a new world, there is humanity and hope.

Quand Ellen Ripley retourne enfin sur Terre, c'est pour découvrir que LV-426, la planète sur laquelle l'équipage du Nostromo est pour la première fois entré en contact avec les terribles/monstrueux Xenomorphes, a été rebaptisée Acheron. Protégés par un régiment de Marines coloniaux, les colons essaient de terraformer la planète balayée par les tempêtes. Au-delà des conditions de vie extrêmes et des combats journaliers imposés par ce nouveau monde, l'espoir et l'humanité demeurent.

Deep in the African rain forest, near the legendary ruins of the Lost City of Zinj, an expedition of eight American geologists are mysteriously and brutally killed in a matter of minutes. Ten thousand miles away, Karen Ross, the Congo Project Supervisor, watches a gruesome video transmission of the aftermath: a camp destroyed, tents crushed and torn, equipment scattered in the mud alongside dead bodies - all motionless except for one moving image - a grainy, dark, man-shaped blur.

子供の頃、クリス・フーパーはモンスターを夢見ていた。しかし、深い宇宙の中では、彼は暗闇と孤立しか見つけられなかった。その後、惑星LV178で、彼と彼の仲間の炭坑作業員は、人間が知る限り最も硬い物質である、暴風雨にさらされ砂を吹き付けた地獄とトリトナイトを発見した。

Ryland Grace is the sole survivor on a desperate, last-chance mission - and if he fails, humanity and the Earth itself will perish. Except that right now, he doesn't know that. He can't even remember his own name, let alone the nature of his assignment or how to complete it. All he knows is that he's been asleep for a very, very long time. And he's just been awakened to find himself millions of miles from home, with nothing but two corpses for company.