Lydia Evans, a wealthy and beautiful noblewoman with poor judgment in men, is betrayed by her lover, Prince Richard, who cheats with her cousin Giselle. She attempts a suicidal poisoning to expose their affair but survives and is sent to a brutal labor camp, where she dies from a plague while regretting her obsession. Regressing to the moment of the poisoning, she slaps herself awake and vows revenge on Richard, Giselle, and a betrayer named Devon. To achieve this, she seeks the aid of Arsen Edis, the empire's coveted swordmaster, revealing her time regression. Skeptical at first, Arsen agrees to help and live with her, but his growing, unusual interest in Lydia hints at complications.