New York: Cupples & Leon Company, (1920). Hardcover first edition - The fourth and last book in this series set during the Great War, the story of two American girls - Joan Mason, an enthusiastic motor girl, and Valerie Warde, a society debutante - who volunteered to serve in the Motor Corps (a fifth book is announced at the end of this volume, but was never published). In this book, the girls go to Paris to celebrate the end of the war. Glossy frontispiece. 212 pp.