As Caster Semenya achieved her dream of winning the 800m World Championship in 2009, rumours of a failed gender test spread. A vicious and voyeuristic media storm erupted and Caster's triumph was turned into public humiliation. With exclusive access, this film follows the shy teenager from a remote South African village as she struggles to come to terms with what has happened and fights to return to competition. With the support of her family and a top legal team, Caster takes the fight to the IAAF, the world's leading body for the sport of athletics. As international lawyers and eminent scientists thrash out what it means to be a woman, the 19-year-old at the centre of the storm wants only to run. A heart-rending and uplifting story of a young woman who overcame incredible odds to become the world's best, only to find that her biggest challenges still lay ahead.