Upon learning that an older woman has moved into run-down, creepy Crabapple Farm, nine-year-old Keeker rides over on her pony, Plum, to find out whether the woman is a witch.
When eight-year-old Keeker gets a pony, she is faced with the challenge of winning the animal's trust and friendship, and they both come to understand the phrase "You scratch my back and I'll scratch yours."