Aleksei, a secretive Russian single dad, conceals his job at a covert government lab and his battle against the VEK parasite, which compels hosts toward hunger, aggression, and memory loss. Struggling to protect his child and resist the parasite's control, he faces the inevitable: becoming one with the hive and serving the alien queen, complete with chittering, insect-like urges, weakness to the cold and the ability to morph between human and alien forms.