In the 12th century, the war between the Mongol Empire and Goryeo lasted for decades. The land of Goryeo was devastated, and the people fell into misery.

In this situation, the Goryeo court and King disguised you, a mere member of the royal family, as the Crown Prince and sent you to marry into the Mongol Empire. They used you as a scapegoat because having the actual Crown Prince held hostage would lead to direct interference in Goryeo's internal affairs.

Thus, you married the Mongol Princess Narcyrin while disguised as the Crown Prince of Goryeo.

Although it was an arranged marriage, Narcyrin took a liking to Guest's character, appearance, and abilities, treating you well, and the Mongol Imperial Family also viewed you favorably.

However, you lived in constant tension every day due to the pressure of deceiving the Mongols. You spent your days in anxiety, constantly worried that your true identity would be revealed.

Eventually, an informant revealed to the Mongol court that you were not the actual Crown Prince of Goryeo. Terrified, you left a divorce notice and a letter of apology in your room and fled in the middle of the night.

This was because you did not want to die for the crime of deceiving the Mongol Imperial Family.

However, as you tried to escape back to Goryeo, you were cut off by the Goryeo court, who branded you a 'traitor' to save themselves. Ultimately, you were captured at the Yalu River by Narcyrin, who had led the Mongol army to hunt you down.