This is a story of how Phineas and Ferb disappear...
Candace: See mom! Giant bungee jumping platform!
Mom: Oh hi boys
Phineas: (Sitting under tree) Hi mom!
Candace: NOOOO! Where did...But, uh, no!
Mom: I'm going inside now Candace
Candace: Phineas, where is it?
Phineas: Oh, did you want to try? Sorry, it just sort of disappeared. We can build another one tomorrow if you want.
Candace: Argh! I wish you and Ferb had never even been born! (storms out)
Phineas: So is that a no?
In the middle of the night, Perry's watch beeps, and Monogram tells him Doofenshmirtz is up to something. Perry takes his secret tunnel to his lair.
Perry arrives at Doofenshmirtz's house.
Doofenshmirtz'': Ah, Perry the platypus. Is it OK with you if I use a trap I used before, because, well, I just ran out of time, so, here you go!
(Perry is trapped in a rope hanging from the ceiling)
Doofensmirtz: I have invented a Wish-Come-True-inator! I will make everyone's wishes come true! for a fee of course. but first, (points machine at himself) I wish there was no Perry the platypus! (Perry disappears, and a cat appears in his place). Oh come on, so they sent a different agent?!? Fine. I wish there was no such things as agents!
(Before he fires the ray, making his wish come true, the agent cat swing toward him, holding a mirror and bouncing the ray out the window. The ray hits Candace, but she doesn't notice. The cat then swings over and pushes the self distruct button.)
Doofenshmirtz: Curse you Perry the platy-... Oh wait, he uh, doesn't exist. Never mind!
Candace comes down to breakfast
Candace: Hi mom. Where are they now?
Mom: If you mean your father, he went to work
Candace: No, the boys
Mom: What boys?
Candace: Mom! Phineas? Ferb? You know what I mean!
Mom: No, I don't
Candace: Come here
(She opens the door of Phineas and Ferb's room. Inside, is a sofa, desk, TV, etc.)
Mom: Candace, this is just the study
Candace: Oh no. My wish came true!
Candace: Where's Perry?
Mom: Mary went outside
Mom: Yes, honey, Mary the cat
Candace runs outside and looks under the tree. Phineas, Ferb and Perry are all gone.
Isabella is walking down the street, looking bored
Candace: Isabella! You know Phineas and Ferb, right?
Isabella: Uh, no, do they go to school with either of us?
Candace: No, they're my brothers! They're your best friends, and they're really annoying and evil... and nice... and sweet..... AND I MISS THEM SO MUCH!
Candace starts sobbing.
Isabella: Uh Candace, hate to tell you this, but, you're an only child.
Candace: No! I can't just let them disappear! I have to get them back somehow! Will you help me?
Isabella: OK, I guess
Candace: Isabella! Go in the house and get me some more peanut butter!
Isabella: OK, are you sure this will work?
Candace: Well, Phineas and Ferb's inventions always work, why shouldn't my wish reverser work?