After watching an alien movie marathon, Candace is convinced Ferb is an alien in disguise, and goes out to gather evidence while the boys begin working on a project for an actual alien. Meanwhile, Doofenshmirtz tries to sell an inator under the guise of a cleaning machine.
Tropes:
- Accidental Misnaming: Monogram tries to tell one of the French Maids that she is breaking his concentration and refers to her as Mimi, but the girl says, "Non 'Mimi'. Fifi."
- Alien Among Us: "Linda" is revealed to be an alien friend of Meap, arriving into Earth to study the habits of "the human female parental unit", as Phineas puts it. The alien leaves after Phineas and Ferb finishes repairing their ship.
- Alien Invasion: The episode opens with the Flynn-Fletcher siblings marathoning a movie about aliens that can impersonate humans trying to take over the world.
- Bait-and-Switch Silhouette: When Candace walks to the backyard, she sees inside a tent a silhouette of what looks like an alien impersonating Ferb and ripping Ferb's head off. In the end, it turns out that Ferb is just fixing a power coupling unit pipe.
- Balloon Belly: Perry knocks one of the little boxes wrapped by the Wrapped-Up-In-A-Nice-Little-Bow-inator into Doofenshmirtz's mouth. Doofenshmirtz pulls the bow, and immediately Doofenshmirtz's entire body expands and fills up the entire room as all the furniture spills out from the box.Doofenshmirtz: Curse you, Perry the Platy— (spits out a chair) Why did I ever order such a large bedroom set?
- Bigger on the Inside: After Perry uses Doofenshmirtz's own inator to wrap up the entire building inside a tiny box, along with Doofenshmirtz in it, Doof points out that the inside of the box is roomier than he thought.
- Big "NO!": Twice by Amanda in the movie when she sees the alien who took over Dr. Abernathy's body. Later by Candace at the end when she once again fails to bust her brothers.
- Brain in a Jar: The alien invaders in the film within the film keep human heads in jars.
- Brick Joke: "The End?" being displayed over the screen of the last movie, which also ends the episode altogether, complete with the same exact ending quote:Amanda / Candace: But it was all right here! Oh, why did I think anyone would believe me? I was a fool! A fool!...
- Call-Back: Candace is sold on the sci-fi movie when she finds out the heroine is named "Amanda", which just so happens to be the name of one of the children she wants to have with Jeremy.
- Call a Rabbit a "Smeerp": One of the ways to tell if someone's an alien is their "strange vocal patterns"; we see it in action when the character in the movie calls a hammer a "krie-bop", among others.
- Continuity Nod:
- Candace goes to hide in the Panic Room from "I, Brobot" again.
- Phineas says the alien they're fixing the spaceship for is a friend of Meap, from "The Chronicles of Meap".
- The End... Or Is It?: The last movie in the marathon ends with this. So does the episode proper.
- Failed a Spot Check: The launch pad actually still stands by the end of the episode wrapped up in a nice little bow, but still Linda didn't even notice it.
- Five-Second Foreshadowing: When Candace goes to fetch her, Linda is seen talking to an uncooked chicken and calling it "little skin bird". Turns out "Linda" is actually a tiny alien in a robotic suit.
- French Maid: Perry's lair is being cleaned up by French girls wearing the stereotypical uniform, and it is really distracting for Monogram. Not so much for Carl, who is able to converse with them in Gratuitous French.
- Gratuitous French: Carl teaches Major Monogram French while talking with the French Maids. When Monogram asks how much they are costing, Carl replies, "Une petite fortune", which means "A small fortune".
- Impossibly-Compact Folding: Invoked with Doofenshmirtz's invention, the Wrapped-Up-In-A-Nice-Little-Bow-inator, which when fired folds up anything it hits inside a tiny box, wrapped up in a nice little bow. Doofenshmirtz demonstrates it by wrapping up a bed set.
- Mistaken for Aliens: Candace thinks Ferb is an alien, after she spent the entire night marathoning alien movies. He isn't.
- Mobile-Suit Human: The "Linda" that Candace brings out of the house to see the launch pad is actually a robot suit piloted by Meap's friend Garbog, who took Linda's place to study human life.
- Puppeteer Parasite: The aliens in the movie series detach the heads of their human victims, store them in jars, and replace them with their own shape-shifting heads.
- Robotic Reveal: The "Linda" Candace brings out turns out to be a robot operated by Meap's friend.
- Shout-Out: The "little skin bird" shtick that "Linda" does is a reference to Mork from Ork doing similar things to food.
- Special Edition Title: The title of the episode is shown much like a cheesy science-fiction B-movie.
- Stock Footage: The scene where Candace runs to the Panic Room was reused from "I, Brobot".
- The Unintelligible: Ferb's cousin (talking to Ferb through the internet) speaks in an accent so thick that, when paired with Ferb moving his mouth weirdly thanks to gum stuck in his teeth, makes Candace think Ferb is speaking an alien language.Ferb's cousin: Oh, I wish you were there, Ferb.
Ferb: So do I. Tell Uncle Angus and Aunt Mora thanks for the candy.
Ferb's Scottish cousin: Too right. Scotland out, PEACE! - Wham Line: When Candace thinks she's finally busted her brothers by getting Linda to see the alien spaceship."Linda": You two have done a great job at repairing my ship.
- What Happened to the Mouse?: Despite the launch pad getting wrapped up in a nice little bow by the inator, the box it gets wrapped in strangely disappears once Linda comes out.
