Grand Tutor Qin knew that Zhou Gu had been betrothed since they were young. He came to know of this the day when the old Duke and the Crown Prince cunningly used the emperor's favor to kick Zhou Gu to the Eastern Palace as their confidant. He had to know everything about this child who was going to become his disciple and who was also the Crown Prince's companion since he was tasked with aiding the Crown Prince. It would aid him in deciding how to properly mentor him.
However, he had never imagined that Zhou Gu's engagement would lead to complications.
Nor did he expect that the Duke hiding Su Rong's identity would waste years of his hard work.