The Father's Day picnic at Elwood City is approaching, and Arthur and his friends try to find a substitute father for Buster while his own father is away. At the picnic, Buster arrives with his father in a hot air balloon, to the surprise of his friends. Prunella wants flash pants and her sister, Rubella, predicts that she is getting them for her birthday, only to be disappointed by a watch instead. and Prunella does not want to be seen without flash pants, since she told Muffy she was going to get them. Meanwhile, Arthur is afraid of being teased when wearing his father's old jacket because he has outgrown his old winter coat. Together, Prunella and Arthur realize that they do not have to hide because of what they wear.