During the transition from the Goryeo to Joseon dynasty, lifelong friends find themselves on opposite sides of an ideological divide centered on patriotism. Seo Hwi (Yang Se Jong), son of a renowned commander, is a steadfast warrior who refuses to tolerate injustice, even as his life spirals into hardship. Despite his struggles, he maintains a resilient smile. In contrast, Nam Sun Ho (Woo Do Hwan), gifted and strategic, faces discrimination due to his mother’s lowly birth. Determined to overcome societal barriers, Sun Ho aspires to pass the military exams, only to see his dreams shattered by a scandal involving his father. To complicate matters further, he finds himself at odds with Seo Hwi due to a misunderstanding.