Episode Title:Mom's Birthday - Journey to the Center of Candace.Episode Description:Mom's Birthday: Candace plans a special birthday party for Mom, and even a song, but Phineas and Ferb's plans keep upstaging her own. In the end, though, they let Candace give Mom the best gift of all. Doofenshmirtz creates a shrinking machine (without the usual inator suffix) that will make whatever he hates (pelicans, instruments that start with the letter 'B', blinking traffic arrows, etc.) shrink to the size of an atom.
Journey to the Center of Candace: The boys build a shrinking submarine so they can go inside Isabella's pet chihuahua and retrieve a sash it ate, but they accidentally end up in Candace's stomach instead while she is on a date with Jeremy. Meanwhile, Perry tries to stop Doofenshmirtz's plans to destroy anyone who can't make up their mind with his newest invention, realizing that it may destroy Phineas and Ferb.