Barney acquires some fortune-telling cards and a secret box. The cards promise magical occurrences, and when his wish is granted, he becomes convinced that the box has mystical powers.

When Arnold the spoiled kid moves to town, he thinks he can walk all over the townsfolk, including Andy and Barney.

After hearing Gomer's stories about how nice Sgt. Carter is, Opie Taylor runs away from Mayberry to join Gomer in the Marines. Ron Howard guest stars.

Opie has his first crush, who ignores him. Barney steps in and tries to give him advice about women, which leads to Opie developing a crush on Thelma Lou.

While walking through the woods, Opie meets Mr. McBeevee, a man who, Opie claims, "lives in the trees" and "jingles when he walks." Andy eventually learns that Opie's new friend works for the telephone company.

Sgt. Carter suspects Gomer has been spending his Sundays at the beach. He then tries to meet the beauties Gomer appeared with in a magazine.

Opie joins a secret club that meets in Jubal Foster's barn. When Jubal burns his own barn down, he attempts to blame the group of boys.