WARNING! SPOILERS! This post contains spoilers regarding the Disney Channel Original Movie, Phineas and Ferb: Across the Second Dimension. View at your own risk, or try not to look for that matter, if you want to see the movie and find out for yourself what happens.
Isabella, you dirty sneak! You snuck that one up on him! On the other hand, there is a bit of logic to this whole matter, so if you get it straight, P.I. strikes again! That's right, P.I. means private investigator, or investigation, whichever works, but that's what I've been doing.
Anyways, onto the scoop. After the events of the movie, when the evil version of Dr. Doofenshmirtz renounces his evil ways and is arrested for his crimes against humanity, Major Monogram and Carl take the main cast of characters to their secret headquarters and prepare for a final memory wipe. Perry is only allowed to stay with his family if no one remembers that he was ever a secret agent. Although Candace saw Perry as a secret agent three times, but all in unrealistic sightings. But just moments beforehand, Isabella sneakily kisses Phineas on the lips in front of everyone, including Candace, Jeremy, Buford, and Dr. Doofenshmirtz, and then tells Carl to fire up Doofenshmirtz's Amnesia-inator, despite Phineas' protests. Now, to think like a scientist. If Phineas did not want to forget Isabella's kiss, and even though no one remembers, that can mean only one thing. This is what Isabella had to do all along to get Phineas' attention. As nasty as this is, what are the chances this will happen again? There is said to be an upcoming episode in which Isabella asks Candace for some romantic advice, but I doubt Candace is gonna be any more helpful besides telling her to impress Phineas.
Ah, well. C'est la vie! Farewell, best day ever! But one thing is for certain. Many more are coming.
Oh, and to answer the questions I laid out in the previous post...
Will the evil version of Dr. Doofenshmirtz succeed in dual world domination?
- No. He repented.
Will Candace finally bust her brothers?
- Not this time. Though for some strange reason she thinks she can contend with a mysterious force and thinks that busting her brothers this time cleared the air.
Will our heroes be forced to bid a final farewell to their favorite platypus, Perry?
- And no.
Huh... Tough break, I guess.