Cho Yeo Hwa has been a widow for 15 years. Her in-laws are the most prestigious noble family in the kingdom. During the day, she leads the life of a widow devoted entirely to her dead husband's memory and rarely ventures outside the gate of her home. At night, Yeo Hwa dons the mask of Hero, who secretly jumps over the surrounding wall to save the helpless.

A father goes all out to clear his daughter from any wrong doing in the murder of his fiancée. When all evidence points to her, he takes matters into to his own hands to save his daughter and outwit the judiciary system.