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. 

King Gyeongjong dies of poisoning and 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.