While at the fun park, the Dino detectives decide to visit the haunted house, but find it a lot more spooky than they expected.

While all of the adults are away on a trip, Araminta's cousin Mathilda comes to babysit, reluctantly bringing with her two teenaged poltergeists who proceed to wreak havoc in Spookie House.

"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 campfires do the trick, or will Isabella just be scared silly?" --p. [4] of cover.

Iggy is delighted when Ada Twist's Aunt Bernice inherits a mansion featuring his favorite architectural periods, but unless the Questioneers can find its missing antiques, the house may be lost forever. Includes information about Art Deco and Art Nouveau, facts about unusual cats, a recipe for ice cream, and a biographical note on Ida B. Wells.

Is Aunt Mathilda's house really haunted by a hungry ghost?