Betty Jo Flynn, Phineas', Ferb's and Candace's grandmother, and Hildegard Johnson, Jeremy's and Suzy's grandmother, have a roller derby rematch, dragging their grandkids into it.

Meanwhile, Dr. Doofenshmirtz tries to destroy a statue of Rutherford B. Hayes, but is hindered by a terrible headache.
* HangoverSensitivity: An obviously-impaired Doofenshmirtz barely has the focus to explain his evil plan of the day and finally begs off after a token effort, promising to be more evil tomorrow.
* TheRival: Betty and Hildegard to each other.