News of Yinreng losing his title rocks the capital and causes the ministers, fearing to side with the wrong prince, to speculate on who may be the new heir. All of them hope that the emperor retracts his command. The third prince, Yinzhi (Prince Cheng), arrives with news. He reports that the recent behavior of Yinreng may have been the work of the eldest prince, Yinzhi (Prince Zhi), and a search of his estate reveals drugs. Enraged, the emperor orders the life imprisonment of the prince. Upon Ruoxi's return to the capital, Yinti delivers a love letter written by Yinsi, which delights and startles her. She goes to Yutan's home to get news and discovers that there are people in the palace hoping to raise Yinti to be heir. With her foreknowledge of history, she wants to write a letter of warning to Yinti but knowing that history cannot be changed, she doesn't. Yinreng to beg forgiveness from the emperor and, again, with her foreknowledge Ruoxi knows that the emperor will forgive him but the time was not right.
Another new year arrives; Yinzhen bestows on Ruoxi a gift of a Mulan necklace while Yinsi continues to write love letters, which greatly moves Ruoxi. Yinsi's supporters urge Ruoxi to reveal her discussions with the emperor but are firmly rebuked by Yinsi. Still believing that history is unchangeable, she tells Yinsi in passing that the emperor still loves Yinreng very much. She decides to write him a warning letter, but before she can deliver it to him, she encounters Yinzhen and during their conversation, Yinsi departs the court.
Amongst the ministers, over thirty support Yinsi to be raised as heir. This leads the emperor to believe that Yinsi has raised a faction for personal gain and strips him of his title then leaves him to be dealt with by the government. He also warns the other brothers else, they would face the same fate and orders corporal punishment on Yinti for speaking up for Yinsi.
废太子之事震动朝野,王公大臣都在纷纷猜测未来太子的可能,生怕站错了队。一众大臣都希望皇上收回成命,此时三阿哥来奏,说明最近太子行为失常都是因为大阿哥施法蛊惑,果然从大阿哥府中搜出草偶,皇上震怒,将大阿哥终身圈禁。