YOU SAID:
gotta see them aliens
INTO JAPANESE
それらをエイリアンに会わなければならない
BACK INTO ENGLISH
Have to meet them aliens
INTO JAPANESE
彼らにエイリアンに会わなければならない
BACK INTO ENGLISH
They have to meet aliens
INTO JAPANESE
彼らはエイリアンに会わなければなりません
BACK INTO ENGLISH
They have to meet aliens
That didn't even make that much sense in English.