She lives with her father and a sibling. One day, her father has a mysterious accident, forces her to look after her younger sibling, the restaurant, and an investigator to find the truth about the accident.

Follow-up to 2014's The Admiral: Roaring Currents, which explores the historic Battle of Hansan Island.

Ace NIS agent Jung Hae-seong is demoted after a mission failure. He goes undercover at a high school to locate King Gojong's missing gold, meeting his teacher Oh Soo-ah, who sees him as her lost first love, stirring old heartbreak.