Dong Yi S01E59 - Jang Moo Yeol Executed for Treason

Then, Dong Yi decides to tell the Queen about the King's plan to abdicate. She also manages to send word to the King about Jang Moo Yeol's plan to frame her and Prince Yeoning. Then, the King's army decide to follow Jang Moo Yeol's men and catch them trying to pay off merchants who involved in the Crown Prince assassination attempt. As his punishment for treason, Jang Moo Yeol is beheaded and his accomplices are exiled and executed. The King cancels his plan to abdicate because everyone is against it. Then, the Queen decides to adopt Prince Yeoning so that he will be a legitimate heir to the throne. In the meantime, Dong Yi decides to leave the palace.