Liz Hickox works in financial services and volunteers for a breast cancer charity. At a bike ride for young survivors, she meets Sarah, who says she has stage 4 metastatic disease. Liz and her husband Brian welcome Sarah into their winter home in Florida and help her train for a triathlon– her single goal before she dies. After they discover the truth, they find other victims of Sarah’s scams and together vow to get her help, turning to an unlikely person: Dr. Phil.