Years ago, in an orphanage, younger twin Susan selflessly gave up her chance to be adopted by a wealthy family, letting her heart-stricken elder sister Beth take the opportunity instead. Time passed, and the elder sister is now the heiress of the prestigious Smith family, relentlessly searching for her long-lost twin. Meanwhile, Susan, married into a family that brought her nothing but suffering, was deceived, stripped of everything, and ultimately pushed to her death. Staring at her bedridden sister, Beth vows to exact revenge for every ounce of pain her sister endured—with her own hands.