Luna Sterling, who trained in medicine deep in the mountains, descends with an old marriage contract. She awakens her Esoteric Insight Eye, which lets her hear the inner voices of human organs. On her journey, she saves Holden Hale who suffers a sudden critical illness, only to be humiliated by the Lane Clan when they tear up the marriage contract upon her arrival. Entrusted by the Hale Clan, she uses her exceptional medical skills to cure Holden's mother and uncovers the hidden traitor in the household. She later repeatedly thwarts framing attempts from rivals, resolves disputes with the Lane Clan, establishes a medical clinic in the capital relying on her medical expertise, and earns Holden Hale's sincere devotion and protection.
