Ask a Foolish Question-Phineas and Ferb invent a supercomputer that can answer anything - even the toughest and most foolish of complicated questions, words, puzzles and ideas. However, Candace discovers this and tries to use the computer to help her bust her brothers, but, as usual, fails. Also, while the supercomputer flies up to Doofenshmirtz Evil Inc., the balcony explodes and the roof explodes and the whole building explodes causing the building to turn black except the middle and the lower floors. Dr. Doofenshmirtz loses his key to his All Purpose-Inator, and the supercomputer has it.
Misperceived Monotreme-Candace takes Perry to the Charity Pet Wash with her, preventing him from learning about Doofenshmirtz's newest evil plan. However, another platypus that escapes from the zoo accidentally completes his mission for him. Phineas and Ferb turn their house into a fun house.