Caught up in a whirlwind of religious fervor over a missionary project in Africa, Alyce Benson impetuously pledges three thousand dollars toward the work. Now she must find a way to get the money.

Alyce harbors a secret passion for automobiles and speed, and she's spent many an afternoon driving around the rustic racetrack in the field behind her home. When she discovers that her father's company has sponsored a racing car that will compete in several upcoming events-races in which the driver will be paid up to five thousand dollars in prize money-she conspires with her father's mechanic, Webster, to train and compete.

But when her friends cast aspirations on Webster's past, she realizes she may have trusted the wrong person with her secret. Will Alyce come up with the money on time, or will she have to choose between her hasty promise and the man who holds a piece of her heart?