Eleven years after the events of "Prometheus", the colony ship USCSS "Covenant", carrying thousands of colonists and hundreds of human embryos in cryo-stasis, makes its way towards the planet Origae-6. The crew is awakened by a neutrino blast and intercepts a transmission sent from Shaw, which they decide to trace to an apparently habitable Engineer home world (referred to as Planet 4), devoid of all non-floral life. When several crew members are infected by the same mutagen encountered by the "Prometheus" crew and give birth to a new breed of Alien, the Neomorphs, the android David 8 rescues them. It is revealed that he brought Shaw to the planet, where he killed all non-floral life and began experimenting on Shaw's corpse to engineer his own breeds of Aliens. His motivations to replace human life with Aliens is made apparent, and with the birth of yet another new breed of Alien, a terraforming expert named Daniels and the remaining crew are forced to flee from the world. After disposing of the Aliens chasing them, the crew members return to the "Covenant" and are put back into cryosleep by someone they believe to be their shipboard synthetic, Walter. Only when Daniels is put in her cryopod does she realize that Walter has been replaced by the identical David. With the crew, colonists, and embryos at his mercy, David contacts Weyland-Yutani back on Earth, stating that while the majority of the crew was killed in the neutrino blast, they would continue to Origae-6.