That's quite a bit to tackle in one question, so be sure to check out the more developed answers posted at the eNotes link below. In a brief summary, here are those elements:
Plot: The plot centers around Paul, whose mother doesn't really love him or her other children and who really wants a better life than her circumstances can afford. Paul discovers that he can predict the upcoming winners of horse races by riding a rocking horse at his house. He hides this from his mother but quietly places bets and makes quite a bit of money which he uses to surprise his mother. It's not enough for her, and he works even harder to make her happy through more intense riding. Eventually, his efforts kill him.
Theme: There are several that could apply. One is that people who rely on money for personal fulfillment will find ultimate disappointment. Paul's mother desires money above all else, which leads her son to his death.
Characters: The main characters are as follows:
- Paul: Paul is an emotional young boy who desperately wishes to win the favor of his mother and make her happy.
- Paul's mother, Hester: Unhappy that she and her husband can't afford the life she desires, Hester notes that her children bring her no joy. Her detachment from her children is the instigating circumstance in Paul's desperate attempts to learn the winners of the races.
- Uncle Oscar: Uncle Oscar assists Paul in his gambling efforts and doesn't shield him from the potentially harmful effects his actions could have.
Setting: This story takes place in England in the 1920s in a fairly affluent neighborhood.