The boys learn about one of Ferb's Victorian ancestors, who helped a scientist create a monster. Meanwhile, Doofenshmirtz recalls the story of his great-great-grandfather Dr. Jekyll Doofenshmirtz.

When Django feels down for not being able to draw art on the same scale as his father, Phineas and Ferb get some big ideas for his piece and the famous "unpainted desert". Meanwhile, Perry faces off against Doofenshmirtz, as he does his best to impress his visiting evil professor.