After the unexpected crisis in No. 141 Space-Time had been completely resolved, Lin Chen prepared to head back.
Before leaving, however, he decided to ask Son Goku about the clues to a form beyond Super Saiyan 4.
Based on his observations during this incident, the clue the system had mentioned was most likely the possibilities of other worlds Son Goku had seen on King Kai's Planet.
Looking back afterward, he suspected Son Goku might not actually have seen parallel timelines, but instead experienced something far more profound than observing them.
Otherwise, how could merely observing parallel timelines have allowed Son Goku to grasp the method of transforming into Super Saiyan 4 all at once?
Lin Chen found Son Goku on Mount Paozu. When he arrived, Son Goku seemed to be packing his bags, as though preparing for a long journey.
"Ah! Mr. Lin Chen! Hello!"
Seeing Lin Chen arrive, Son Goku set down his luggage and greeted him.
"Are you going on a trip?"
"Something like that." Son Goku smiled and pointed outside. "Mr. Lin Chen, how about we talk outside?"
"Sure."
Lin Chen nodded. Just before stepping out, he suddenly heard sobbing from inside the room. Turning to look, he saw Son Goku's wife, Chi-Chi, slumped over the table in tears.
Lin Chen frowned. Only after they went outside did he learn why.
"Mr. Lin Chen, I'm actually planning to leave Earth and travel through the worlds out there. And I don't intend to come back to Earth. Once I'm done traveling, I'll go live with King Kai," Son Goku said.
"Why?" Lin Chen asked, somewhat puzzled.
"This incident made me realize that my Saiyan nature still remains inside me. That's too dangerous for Earth."
Son Goku clasped his hands behind his head and gazed toward the distant forest.