ZAT wa saikin tōchaku shita uchū kaijū ga warui kaijūna no ka yūkō-tekina kaijūna no ka o handan shiyou to shimasuga, dokuji no mokuteki o motsu jaakuna eirian ga Moriyama ni tori tsuite iru tame, chōsa wa samatage raremasu.
ZAT tries to determine if a recently arrived space monster is a bad kaiju or a friendly one but their investigations are hindered when Moriyama is possessed by an evil alien that has its own agenda.