Yeo Hwa marries into Joseon's most powerful family as the eldest daughter-in-law, but her life takes a tragic turn when her husband dies on their wedding day. Forced into a life of mourning and confinement, she longs for freedom beyond the gate.

By night, she secretly dons a mask and roams the rooftops, helping those in need. Her double life remains hidden—until she crosses paths with Park Soo Ho, a sharp, no-nonsense officer of the Forbidden Guard. Handsome, skilled, and relentless, Soo Ho keeps showing up wherever she goes in disguise.

Is it coincidence or fate? And does he know her secret? Yeo Hwa’s carefully guarded double life is on the verge of being exposed.