The film shifts the focus from the Engineers—the mysterious creators introduced in Prometheus —to the synthetic life form David, portrayed by Michael Fassbender. David’s descent into a "god complex" serves as the primary engine for the plot. He views humanity as an obsolete species and seeks to engineer a "perfect" successor: the Xenomorph.

César tried to stop the projector. The switch wouldn't move. The film kept rolling. Then, from the speakers — a voice he didn't recognize. Deep. Guttural. Speaking perfect, dubbed Portuguese: