Presents the further adventures of a motorcycle-riding mouse who goes to school and becomes the instigator of an investigation of rodents and the peacemaker for two lonely boys.
Penny feels guilty after taking a beautiful blue marble that she sees in Mrs. Goodwin's grass, but gets a pleasant surprise when she goes to return it the next day.
Owen's parents try to get him to give up his favorite blanket before he starts school, but when their efforts fail, they come up with a solution that makes everyone happy.