attacco alla Terra was released in the year 1983。attacco alla Terra is also called as Xtro, Xtro - Nicht alle Ausserirdische sind freundlich, Judas Goat。

Tony's father Sam, abducted by aliens three years earlier, returns to earth and seeks out his wife and son, but Rachel has since been living with Joe and the reunion is awkward. Joe doesn't trust Sam, and Rachel can't quite decide what her feelings are for her two men. Sam is not the same as when he left, and he begins affecting Tony in frightening ways.