Theresa Abbey, whose real name is Tia Sullivan, was separated from her father Frank at a young age. Suffering from a heart condition and unable to speak, she was adopted by the Abbey family. However, the Abbey family only saw her as a tool - her sister Holly impersonated her to go to school, while her adoptive father and brother tried to harm her for money. During her escape, she was rescued by her biological father Frank, who had become a wealthy businessman. When they met, they both felt a strong sense of familiarity. Frank took her back to his home, and just as they were about to reunite, Holly appeared again, seeking to replace Theresa and inherit the Sullivan family's wealth...
