The Plot or 'flow' of the Rocking Horse winner is about a boy that has the uncanny ability to pick the winners of various horse races. He does this while sitting on his rocking horse. Learning that his family is without means and according to his mother, 'the poor relations', he sets about to prove that he has more 'luck' than his father.
He hears the house whispering to him that there must be more money, urging him to continue to ride the rocking horse. When he wins he gives the money to his mother, hoping that it will solve their problems. He doesn't want his mother to know that he has this ability, and so enlists the help of his Uncle to place the bets on the horses and to give the money to his mother. When she receives the money on her birthday, instead of being happy or grateful, she is cold and indifferent. The house does not stop whispering, instead it becomes louder and more frequent. And, it seems that the more the boy wins, the more urgent the voices become. Finally, he has a chance to win more than 80,000 pounds for his mother by betting on a long shot in the Derby. They find him the next morning unconcious, but not before he's had a chance to give his Uncle the horse's name. Later on, the boy dies, and his parents don't seem too broken up about it. The Uncle, knowing what has happened, berates them as useless and pathetic individuals.