Nine very different adults are brought together to face a challenge that has always defeated them - learning to swim. Instructor Linda has seen it all before. She knows that most of the women will be petrified of getting their hair and faces wet, the men will be embarrassed by their lack of prowess, and all of them will probably have to conquer demons that run much deeper than a fear of water. Fifty-six-year-old Sandy from Southend-on-Sea is enthusiastic to begin with, but at the end of the second week, still reluctant to get her face wet and asking for armbands, Sandy reveals stories of a cosseted childhood that still haunts her adult years - the girl who was never allowed to play with other children has become the woman who hides behind an ever present mask of make-up. Thirty-seven-year-old Mandy, almost too afraid to don a swimming costume at the beginning of the course, is fighting a feeling that no one ever expects her to achieve, while 39-year-old kitchen salesman Wyn's floundering breaststroke speaks of a nervous history that he is resolved to master in what becomes his own version of chlorine therapy. After six weeks, Linda leads her protégés to the ultimate test in the big pool. It's sink-or-swim time.