Great Tang: My Father Is Li Shimin

My name is Zhang Chen. I transmigrated to the seventh year of Zhenguan and became Qin Qiong's adopted son. What I never expected was that I wasn't the only one who had transmigrated: my biological father had too, and he'd become Li Shimin, the greatest emperor of all time? “Dad... It's me, your son, Zhang Chen!” Zhang Chen looked at Li Shimin, overcome with emotion. But Li Shimin did not answer. Instead, he looked at Zhang Chen and said, “You are indeed my son. There's no doubt about that.” “No, that's not what I mean...!” Zhang Chen tried to explain further. Li Shimin only smiled and shook his head. He had no intention of letting Zhang Chen say anything more. Zhang Chen didn't understand. Why wouldn't his own father acknowledge him, when he really was his father? Why...?