King Yeongjo decides to have a public hearing and listen to the difficulties of the people. He promises to reduce tax by half. The nobles are angry that landlords will be compensating for the remaining amount. The dispute is to be settled by a vote.
King Yeongjo decides to abolish the section chief of personnel. The senior officials are furious. Prince Milpoong walks into the palace himself and kills himself. Inspectors at Saheonbu support the King’s decision. Lee Yin Jwa and Wi Byeong Joo are executed.
The senior officials gather Saheonbu soldiers to arrest Lee Yin Jwa’s father-in-law and his family. They protest against the King’s appointment of Namins. Yoon Yeong tries to help Prince Milpoong get away safely to Qing Dynasty but is killed in an accident. Min Jin Heon supports the King’s reform.
Lee Yin Jwa is arrested and brought before the King. Prince Milpoong, however, is still on the run. The King begins to appoint members of the Namin Party to office as he had promised during the revolt. Both the Patriarchs and Disciples begin to protest against the appointment.
The rebels are ambushed by the government troops and are defeated. Prince Milpoong and Yin Jwa, however, manage to getaway. The Chairman agrees with the King to share government positions with the suppressed Namins, which conciliates the Namins associated with the rebels. The government troops return in triumph, and the King congratulates them.
The King tries to persuade the Chairman to share the palace positions with the Namin in order to weaken the rebels' motivation. The palace doesn't have enough troops, so they have to decide where to place them. Hearing that the rebels are coming for the capital, high government officials are the first to flee. The royal troops decide to ambush the rebels.
Rumors are spreading that the King will abandon the palace and his people and escape from the plague. The number of plague patients is climbing. Dal Moon and his men discover that the wells could have been poisoned systematically. Prince Milpoong is suspected to be behind all this. As the commoners start to go wild, the King shows up to console them.
The Crown Prince is enthroned with the backing of Queen Dowager. But Lee Geum is surprised to hear that his closest allies decided to resign and leave the palace. The deal was sealed so that the Patriarchs could support the king. Meanwhile, Wi Byeong Joo escapes from his place of exile, and an epidemic begins to spread.
King Gyeongjong dies of poisoning, and a rumor spreads that the Crown Prince let him die intentionally. The Chief Justice blames the Crown Prince and objects to his enthronement. The Crown Prince himself questions himself in self-doubt. But with his former teacher's support, the Crown Prince goes to meet Queen Dowager and take control.
Moon Soo finds Prince Milpoong in his place of exile and gets him to reveal his plans. He had left a blood mark in the Royal Infirmary so that the Crown Prince would stop the medicine from being given to the King. The poison turns out to have been imported from Qing and is known to have no antidote. The Crown Prince does everything he can, but the King dies.
King Gyeongjong suddenly falls ill, and there are suspicions that Prince Milpoong sneaked into the Royal Infirmary. The Crown Prince stops the royal doctors from giving medicine to the King in case it was poisoned. But his position as Crown Prince is endangered as he comes under suspicion of trying to take the throne. Private doctors are called to the palace to examine the King.
Byeong Joo set up a treason case, accusing the son and grandson of two Disciples officials of plotting against the king. The Crown Prince visits Jin Heon privately and asks him to side with him for the time being instead of supporting Prince Milpoong. The Crown Prince notices that the posts that were put up around the city contain a secret message from Dal Moon. The king decides to question the alleged rebels themselves, but Jin Heon intervenes.
The King is convinced that the Crown Prince should take his place, just as the appeal requested. However, the Crown Prince realizes that he's been framed and decides to prostrate before the King and ask for reconsideration. Prince Milpoong has a further plan that will bring down the Crown Prince, and he's waiting for the right time to implement it. The Disciples ask Queen Dowager to persuade the King not to blame the Crown Prince.
Ji Pyeong is murdered, and Prince Yeoning is witnessed to be the murderer and it arrested by Saheonbu. He is investigated by Saheonbu but is not willing to speak the truth. Meanwhile, behind the murder cases are what is known as master-murderers and the murderer of Ji Pyeong turns out to be a little girl wearing a tattoo. Moon Soo and Yeo Ji investigate what's behind the murder cases.
Prince Yeoning returns to his former colleagues Park Moon Soo and Yeo Ji and tells them he was behind the investigation on exam corruption. Prince Yeoning is now determined to become king. But the Minister of Personnel meets with the king and tries to persuade him otherwise. Meanwhile, the Patriarchs manipulate public opinion so the exam corruption case won't attract too much attention. And the Saganwon is out to stop the king from putting pressure on the Patriarchs.
Prince Yeoning decides to testify at the Supreme Court of Saheonbu. He confesses that he substituted for Tae Pyeong at the state exam and asks to be exiled for this crime. The officials, however, do not want to believe his accusations of Prince Milpoong. The Head of Saheonbu decides to arrest Prince Milpoong, and everything seems to go as planned.
Moon Soo finds out that the Roh Tae Pyeong he was chasing after was Prince Yeoning. Prince Yeoning decides to spread a rumor about Prince Milpoong and his evil deeds. The rumor eventually reaches the king and the royal court, and the king orders investigators to submit a detailed report. Yeo Ji realizes that she had acquired decisive evidence for where the body of Tae Pyeong is buried.
The relation between Prince Yeoning and Tae Pyeong remains a mystery. The inspectors of Saheonbu are determined to investigate the murder of Yeo Ok and prove that Prince Milpoong is guilty. Meanwhile, Yeo Ji steals a box from Prince Milpoong supposedly containing valuable evidence. Prince Yeonryeong does not want to use illegal force to stop Milpoong from coming to power.