Phineas and Ferb Season 4 Episode 25 - Druselsteinoween Episode Title: Druselsteinoween Episode Description: When Vanessa learns that her father has inherited a Drusselsteinian castle right next door to her she seizes the opportunity to throw the biggest Halloween bash ever. The whole town is there, including Phineas and Ferb, who act as the event's party planners and DJs. Meanwhile, Doofenshmirtz enlists Perry to help him find a large, hidden treasure that his Great Aunt has placed somewhere within the castle.