A reward is being offered to the person who captures the Headless Horseman. Penny and her friend Louise go off to Red Valley in a quest to win the reward. But will they find the Horseman? And will they survive the unexpected flood that hits? Find out in Hoofbeats on the Turnpike!This book is from the Penny Parker series by Mildred A. Wirt, also known as ghostwriter Carolyn Keene, of the Nancy Drew series of books.