One Good Scare Ought to Do It!, The Monster of Phineas-n-Ferbenstein

When Isabella falls prey to hiccups, Phineas and Ferb gather the kids together to help scare them out of her, using a remote controlled haunted house. Meanwhile, Doofenshmirtz sets out to destroy his mentor's hideout, so that no one could discover his secrets, but not if Perry has something to say about it!
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.