Haechi - Season 1 Episode 34 King Gyeongjong’s Death
Overview: 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.