Gwen Harrington was once the cherished daughter of the Harrington Estate, adored by her father and brothers. But after Isabel Harrington, their adopted daughter, entered the family, all their love and attention shifted to her. Isabel secretly schemed against Gwen until Gwen was tragically killed, only to be reborn and given a second chance at life. This time, Gwen exposes everyone’s carefully hidden lies during her coming of age ceremony and takes the initiative to break off her engagement. Using her mother’s past kindness to the Emperor, she asks to be appointed The Saint and retreats to the Waterspring Abbey to train. There, she masters the arts of medicine and poison, while gradually falling for Elliot Sterling, the Regent Sterling who was once helped by Gwen when they were children. As Isabel’s cruel deeds are exposed one after another, Gwen’s father and brothers finally see her true colors and bitterly regret their past mistakes, desperately begging Gwen for forgiveness.
