Waitress Jennie Jones is a naive young woman from small town Athens, Nebraska. With $1,000 inheritance money from her grandfather, she has come to the big city happily to fulfill the terms of the inheritance: to buy a mare, specifically a retired race horse named Firefly. Much like Jennie's relationship to her grandfather, Firefly is a direct descendant, two generations ago, of a winning race horse Jennie's grandfather bred. Jennie's goal is to allow Firefly to live out the rest of her life in the grand style Jennie believes she deserves. To buy Firefly, Jennie, as per her grandfather's suggestion, enlists the help of two horse racing gamblers, "Tip" Bailey and "Jinx" Donovan. What Jennie is unaware of is that Tip and Jinx are broke shysters, who will willingly use Jennie and her inheritance to pay off their debts and pocket more than a little money for themselves. What Tip and Jinx try to pull on Jennie changes with her changing fortunes or potential fortunes. Further adding to the complications are Tip and Jinx's own thoughts about other ways to hit it big; an unscrupulous horse owner named Pop Reynolds; a jockey named Chalky Williams for who Firefly will only run; Mark Downey, Jennie's boss in the city who is immediately smitten with her and wants to prove that he is not after whatever money she has or may have; and a winning sweepstakes ticket for the Grand National Lottery.