D. W., Arthur's self-assured little sister, is the central character in a new series written for beginning readers. It's D. W.'s first day in gymnastics class, and she knows it all. For D. W., touching toes and skipping in circles is easy, but when she is called upon to do a forward roll, she can't.

After a long week of practice, D. W. masters the forward roll only to discover the new task at hand is the backward roll.