Equestrian Mary King has been on a winning streak since she was 13. Substituting an injured friend in the arena, she mounted a horse she'd never ridden before. Naively, she asked if she should try to win. When the answer came back yes, she did just that: she won. In almost forty years since that day, she's said goodbye to a beloved equine companion who fell in action, found a balance between being a horsewoman and a mother, and - last but not least - won three Olympic medals. A tribute to the distinguished reign of one of Britain's longest-serving Olympians.