When Phineas and Ferb's friend Isabella develops a terrible case of the hiccups, the boys create a super scary haunted house to try to scare them out of her. Will the house filled with wicked werewolves, creepy crawlies, and villainous vampires do the trick, or will Isabella just be scared silly? Then, the thrills continue when Phineas and Ferb try to find their very own mummy.