Ruler - Master of the Mask Episode 30

King went to Ga-eun to leave Dae Mok's place, but she asked him to save the prince. King was upset hearing that and shouted why he wanted to save her enemy who killed her father. Ga-eun said it was not the prince killed her father and asked King to find a way to save the prince. 

The King goes to Queen Mother and asks for help. To show their alliance, King announced the daughter of the second vice-premier was selected as new Queen. 

Prince cannot eat anything for worries of Chung-woon. Hwa-gun promised him to prepare an antidote. 

Meanwhile, Dae Mok called Gon and said he would never tolerate anyone even his grandchild who betray Pyunsoo and warned him what would be the best way to serve his master. 

Gon, then said to Hwa-gun that he found a place to find antidotes and brought her to somewhere. 

Prince went to join Pyunsoo. Dae Mok urged him to drink the drug threatening him to kill Ga-eun. Dae Mok prepared three times the higher dose to kill him not poisoned him. Prince after drinking the cup throws blood and falls.

Hwa-gun who got the news late became furious and requested Gon to find his body. 

King throws a feast to celebrate new Queen selection. At there he made a fake mistake of Woo Bo and kicked him out of the feast. King, then makes everyone to drink the special liquid. Everyone but Pyunsoo's people had, and all were addicted to the drug. Dae Mok appeared to warn that everyone who had the drink should take their pill regularly otherwise they will die. 

Dae Mok controlled King with Ga-eun to wipe out Queen Mother's power from the palace. King also was presented at Prince's joining act. 

King came to see Ga-eun after finishing everything. She tears and asks about the prince. King said sorry for failing to save the prince, however, he would protect her.