Meet Felicity Merriman, a spunky, spritely nine-year-old girl who lives in Wiliamsburg, Virginia, in 1774, just before the Revolutionary War. She grows impatient doing "sitting down kinds of things", like practicing her stitchery or handwriting. She would much rather be riding horses. That's why Felicity is so excited to hear about a new horse in town. But the horse is owned by Jiggy Nye, the cruel tanner who beats his animals. Felicity sneaks off to visit the horse and falls in love with the copper-colored mare, which she names Penny. When Penny's life is in danger, Felicity knows she must help.