Kwon Si-jun, once an illegitimate child, is adopted into the powerful Daeseo Group. Sa In-seo, a woman labeled as the family’s sinner, has endured 17 years of abuse, surviving by suppressing her emotions. Believing Si-jun to be her only support, she is shaken when his words push her to finally decide to escape.

But as she tries to break free, Si-jun reveals an obsessive and incomprehensible side of himself, confessing feelings she can no longer trust—no matter how he calls it love.