After leaving the base, Gu Zichen didn't hide.
He returned to the Gu Family home.
The Gu Family home had always been a place for him to conceal his identity. After graduating from university in the United States, the base had him return to the Gu Family and only contacted him for missions. Thus, for three years, he made great strides in the Gu Family, becoming a household name in Shanghai.
Once Gu Zichen returned home, he started to slowly establish contact with the others who were scattered and on the run, devising ways to hide their identities one by one.
Because the base wouldn't make a move against them individually, believing that Gu Zichen had something important in his hands, they needed to ensure that everyone was within their field of vision before they could carry out a collective assassination.
Gu Zichen was the base's most capable operative. What the base could think of, he could too.
