During the Joseon Dynasty, the Secret Royal Inspectors are the eyes and ears of the king. They travel the provinces undercover and listen to the plight of the common people, investigating abuses and corruption of government officials.

In the modern age, Jang Bong-hwan is a chef who works for the country's top politicians at the Blue House. He has a free spirit, but he one day finds himself in the body of Queen Cheorin in the Joseon period.

Ba-Woo is a degenerate man. He gambles, steals, fights and will do bossam (customary remarriage procedure where a widow is kidnapped) for money. He hides his real identity. While performing a bossam, he mistakenly kidnaps Princess Hwain. She is the daughter of Prince Gwanghae and the daughter-in-law of his enemy Lee Yi-Cheom. For a secret political agreement, she married the older brother of a man she loved, but, on the day of her wedding, her husband died. She then became a widow.

Back at square one as divorcees, four siblings take another shot at love and dreams — after mustering up the courage to convince their parents first.

A K-fantasy action unfolds as the Nine-tailed fox makes a crash landing in the year 1938, an era of chaos, and he struggles to return to the present.