For an assignment that requires her to write about her "Most Interesting Relative", Brenda asks her parents for help. Lester suggests his aunt Lucy who was a woman brakeman. After Mary hears about Sandra's supposed relative who was a Moroccan prince, she searches through an old trunk to find information about an interesting relative of hers. What she finds is that she had an uncle, Corporal Mortecai Hurley, who was in the Civil War's 54th Infantry. She persuades Brenda to re-write her paper on Mortecai.