Jang Ok Jeong confirms to Dong Yi that she is not going to accept her truce as they are enemies. Then, guards storm the Crown Prince's palace because someone has stolen the Crown Prince books. But, the Crown Prince saves the prince by telling the King that he has give it to him. Jang Moo Yeol goes to see Dong Yi and to convince her to reveal the truth about the Crown Prince, but she rejects it. The Crown Prince and Prince Yeoning meanwhile sneak out of the palace to go to a festival. But the Crown Prince get arrested and dragged away to a police station. The palace is in chaos when they find out that the Crown Prince is missing but he is about to be punished for stealing.

Everyone searches for the Crown Prince. He doesn't tell the police who he is because he is worried something bad will happen to him. Cheon Soo finally finds him and brings him back to the palace. He is very weak and ill. Jang Ok Jeong is furious and blames Prince Yeoning. Because of that, Southern and Disciples' faction want Dong Yi and her son to be exiled from the palace because they put Crown Prince's life in danger. When Crown Prince gets healthier, he tells his mother that he knows what his illness is and doesn't feel he is worthy of his position as Crown Prince. He then goes to meet the King and tells him the truth.

When the King knows about Crown Prince's illness, he is furious. Jang Moo Yeol also spread the news so that officials will stop supporting Jang Ok Jeong. So, they all stop supporting her. Furthermore, she is arrested for attempting to kill Dong Yi and the prince. She wanted revenge and ask her brother to start a fire at the palace so that the assassins can sneak in to kill Dong Yi and the prince during the chaos. During the fire, the assassin sneaks in and tries to kill the prince but Dong Yi throws herself in front of her son and gets slash by the sword.