Ruler: Master of the Mask

In order to ensure that her son will be a good and wise King, his mother tries to delay his birth. Someone has poisoned the young Prince.

Hwa Goon tells her grandfather that she wants to be the Crown Princess. The Crown Prince sneaks out of the palace to look for Woo Bo.

The Crown Prince meets some colorful characters while looking for Woo Bo, who is not what he expected.

The Crown Prince finds he cannot stand by and watch a villager lose his hand for stealing some water to save his family, but there are unexpected consequences.

Hwa Goon vows to win the Crown Prince's heart. The Crown Prince finds out why he must wear the mask.

The Crown Prince tries to save Ga Eun's father, but that proves to be more difficult than he expected.

The Crown Prince asks Woo Bo how to eradicate the Pyeonsoo-hwe. King Yeongjo looks for another Lee Seon.

Eun Ha finds proof that her father was innocent. The Crown Prince teaches Lee Seon how to impersonate him.

Hwa Goon helps the Crown Prince and Dae Mok tells Lee Seon that he must now wear the mask.

After five years, Chilpye is a thriving marketplace and the Queen Regent has not yet stepped down.

The Crown Prince rescues Ga Eun but keeps his identity a secret. The palace is surprised when Lee Seon makes a ruling that does not side with the Pyeonsoo-hwe.

The Crown Prince persuades the largest merchants to rise up against Dae Mok, and then goes off in search of copper.

Ga Eun is desperate to find the pot that will clear her father's name. Lee Seon is heartbroken to have to pretend he does not know Ga Eun.

The Crown Prince goes to the meet point to catch the copper thieves in the act.

The Crown Prince uses the stolen copper to further his plan. Lee Seon finds a way to invite Ga Eun back to the palace.

Dowager Queen has her own plans for Ga Eun. The Crown Prince overhears Ga Eun pining for Chun Soo.

Hwa Goon makes a deal with her grandfather to save the Crown Prince. People are starting to figure out who the Crown Prince really is.

Yang tries to draw the location of the poison. Lee Seon sneaks out of the palace to see his family and runs into some people he did not expect to see.

The Crown Prince is worried that Ga Eun has made a terrible decision. Ga Eun figures out who really drew the map.

Dowager Queen enlists Ga Eun to help her figure out what hold the Pyeonsoo-hwe have over the King. Word that the King is a fake has begun to spread.

The Crown Prince has to decide if moving the army from the border to attack the Pyeonsoo-hwe is the right move.

The Crown Prince asks Hwa Goon to help him stop Choi Heon's army. The palace prepares for the Dowager Queen's birthday celebration.

Lee Seon tells Ga Eun that he did not kill her father. The Dowager Queen plans to use the Crown Prince to fight the Pyeonsoo-hwe.

When the Crown Prince sneaks into Dae Mok's house, he learns more than he bargained for. The Dowager Queen starts the Queen selection process.