A short while later, Feng saw that everyone he had brought to the moon had something to do except him. He called to the Steel-Wing Dragon and flew toward the Earth-Moon Passage.
According to the original story, people from the Ninja World would not find this place until Otsutsuki Toneri revealed himself years later.
But Feng and Black Zetsu had both reached the moon through the Earth-Moon Passage. There was no guarantee someone else would not follow their trail here.
Feng did not want anyone interrupting his work on the Tenseigan. Until it emerged, he would guard the Earth-Moon Passage himself and make sure no one got through.
"Uchiha Feng?! Where are you going?"
Outside the Palace, Black Zetsu saw Feng riding the Steel-Wing Dragon toward the Earth-Moon Passage and hurried out to question him.
His mother was inside the moon beneath their feet. Feng knew about her and was, for now, his partner. Black Zetsu did not dare let Feng out of his sight.
"Heh. Nowhere special. Follow me if you're worried."
Feng smiled and answered casually, without even making the Steel-Wing Dragon stop.
Black Zetsu said nothing. He slipped underground and hurried after the Steel-Wing Dragon.
Uchiha Feng had received his side of their bargain, but Black Zetsu had yet to receive his. If Feng meant to return to the Ninja World and expose everything, Black Zetsu feared that failing to follow him might cost him even his pawn, Obito.
A short while later, the Steel-Wing Dragon stopped at the lunar entrance to the Earth-Moon Passage. Feng jumped off its back and surveyed the entrance.
Watching from a distance, Black Zetsu guessed Feng's intentions almost immediately.
"You're going to guard this entrance? Yourself?"
Still, he could not understand why Feng would do it personally instead of leaving