Journey to the Center of Doofenshmirtz's Basement

The twentieth episode of Season 39. Doofenshmirtz ventures through his basement to find parts for an Inator. Phineas and Ferb have a mock zombie apocalypse.

Episode Summary
One day, Doofenshmirtz is completely blank on Inator ideas. He asks Norm what he should do. Norm suggests an Inator that turns things into broccoli. Doof says that's been done. Then Norm suggests an Inator that influences humiliation. Doof says that's been done too. Then Norm is about to suggest an Inator that brings things into outer space. Doof says that he keep suggesting Inators he's already made, and that he needs new ideas. Then, Doof knows what he's gonna do today. He decides to go into his basement and look for Inator parts. Meanwhile, Phineas and Ferb are listening to a zombie story that Irving is telling. Baljeet believes none of this malarkey. Phineas thinks it would be cool to live in a zombie apocalypse. Phineas knows what he's gonna do today. Then he wonders where Perry went. Perry is on his way to Doof's place and Monogram is telling him that Doof has been in his basement all morning. He should go over and see what he's up to. Perry heads to the basement of DEI. He bursts in and is trapped in a mouse trap cage.