When Ashleigh Griffen first found Lightning, the poor mare was thin and sick. But now, because of Ashleigh's loving care, Lightning is a beautiful, healthy horse. Ashleigh dreams of all the wonderful things she will do once her family has officially adopted the mare.

But then the humane society announces that they've found another home for Lightning—and they're going to take her away right before Christmas! Ashleigh is frantic. How can she make them understand that Lightning belongs to her?