Ep 15. Druselsteinoween / Face Your Fear

In Phineas and Ferb Season 4 Episode 15 titled Druselsteinoween/Face Your Fear, the boys are in the spirit of Halloween and decide to create a haunted house in their backyard. In usual Phineas and Ferb fashion, the haunted house isn't your average spooky attraction. Instead, it's been designed to tap into everyone's deepest fears and push them to face these phobias.

Meanwhile, Dr. Doofenshmirtz, the boys' arch-nemesis, is also preparing for Halloween. Proud of his invention, a new -inator, named the "Repulse-inator," which can repel any object by making it unattractive, he plans to use it on the other candy in the tri-state area so people will come to his house for treats instead. However, he ends up shrinking his own head because of an accidental malfunction, causing his face to become terrifying to look at.

Simultaneously, Vanessa, Doofenshmirtz's daughter, is trying to help her father out by posing as a witch and scaring off all the posers trying to take advantage of the situation. However, she finds out that her dad is the one behind the big-headed scare, leading her to question his actions and motives.

As the episode progresses, the three storylines intertwine with the boys' haunted house, Doofenshmirtz's invention, and Vanessa's doubts about her dad all colliding. The boys' friends are all invited to the haunted house to confront their fears and find themselves facing their biggest phobias head-on, while Candace, their sister, is concerned that their mother will discover their spooky undertaking and doesn't want to be caught in the middle of the conflict.

As the night carries on, the Repulse-inator explodes, causing a chain reaction of events that ultimately leads to a resolution for all of the characters. Doofenshmirtz's face returns to normal, Vanessa learns that her dad's actions were not as nefarious as she expected, and Candace ends up enjoying the haunted house when she sees that it's not causing any problems.

The episode ends on a happy note, as all of the characters put their fear behind them and enjoy the rest of Halloween night together. As always, Phineas and Ferb's creative minds and wit lead them to yet another eventful and entertaining adventure.