At the moment Fang Chuning made the suggestion, Xie Jue was very moved. If it weren't for Fang Chuning's insistence on recovering his memory, he wouldn't want to take Fang Chuning to Beiman. As Fang Chuning mentioned, his body is very weak now, residual poison remains. What if a trip to Beiman worsens his condition? If he has let go, then not going to Beiman is fine.
Traveling the world was originally a promise between him and Fang Chuning.
"Don't you want to find your family?"
"I don't want to!" Fang Chuning's smile slightly waned as he spoke softly, "Strangely enough, I feel a deeper familiarity with you than with my father. Isn't that strange? Now, my mother is living in Jiangnan without worries and away from the troubles of the capital, and I am no longer worried about her."
"It's not actually that strange. You've spent little time with the marshal since childhood, so it's natural to feel unfamiliar with him."
