Sue Ellen Moves inArthur goes around the neighborhood, noting who has and hasn't been friends. When they all go sledding, they notice a new family moving into down. Buster becomes convinced aliens are involved when the lights go on and off at random, but no one seems to be inside. He has to figure out what to do when the new girl is joining their class, especially when Bitsy invites her family to dinner.
Tropes for this episode include:
- Doing In the Wizard: Francine points out that some houses run on timers. Therefore, the "invisible" people aren't there. Buster says thinking like that gets Earth conquered.
- Gossip Evolution: The rumors about Sue Ellen bloom on the telephone calls until Binky tells them all he can't understand what they're saying. Prunella thinks that Sue Ellen's from a family of cat burglars, Arthur believes that she is a spy, and Buster assumes she is an alien.
- Memetic Badass: In-universe, Prunella and Arthur both imagine this of Sue Ellen:
- Prunella thinks that she's a cat burglar who has robbed the Louvre of all their paintings. The Imagine Spot shows her avoiding two security guards and outwitting them. When one tries to hold her up with a croissant, she uses rocket boots to blast through the roof windows and to her getaway jet.
- Arthur proposes that Sue Ellen is a preteen spy that stole an important disk from a computer scientist, holding his computer hostage with a pot of coffee. When she gets what she wants, she destroys the computer anyway, surrenders the disk to her bosses while driving a car, and decides she can go to Elwood City to lie low. Though she can't pronounce the name of her home country.
- Mundane Solution: It turns out Bitsy figured out who Sue Ellen was by doing one simple thing: talking to her family.
- Nice Girl: Sue Ellen is very nice to Buster and Arthur when introducing herself. She also invites Buster out for hot dogs at the end.
- Only Sane Woman: Francine is the only person who doesn't get involved in the gossip surrounding Sue Ellen. She rightly points out there's a logical explanation for the lights turning on and off.
- Skewed Priorities: When Buster has an Imagine Spot of Sue Ellen and her family sending him to space in a bubble, he says he wishes he had grabbed some cookies first.
- Split-Screen Phone Call: The above Gossip Evolution scene features this as the kids call each other. Binky, however, can't figure out how to dial in.Binky: Hello? Hello? (leans out of his square) What is everyone talking about?! (everyone else hangs up, and one person picks up the phone) Hey, did you hear about the new kid?Mr. Ratburn: (annoyed) Who is this?Binky: Oops! Wrong number!
- Vanity License Plate: Buster's imagination of Sue Ellen as a superspy has her driving a red sports car with the license plate SULN (an abbreviation of her name).
- Vitriolic Best Buds: According to Arthur, Brain and Binky have this relationship. Binky will destroy Brain's art For the Lulz, but Brain has the grace to laugh about it.
The Perfect BrotherArthur likes having friends over because they make home life better. He's thrilled about learning the Brain is staying for a few days, being a brother he's never had. Unfortunately, the good feelings go away when Brain is revealed to be neat, polite to the Reads, and proactive about homework.
Tropes for this episode include:
- Actually Pretty Funny: Arthur and Brain share a smile when they realize that neither of them is perfect, and it's okay to be jealous of your friend.
- Always Someone Better: Arthur gradually becomes jealous of how the Brain can win everyone else over and seems to be perfect. He finds out that Brain was just being polite as a guest — at his own house, he is messy and doesn't get the door for his father when Arthur does.
- Big Brother Bully: Invoked. D.W. has an Imagine Spot that Brain will be another Arthur and corner her to wrap her up like a mummy. She thinks about spending the weekend at Grandma's. Ironically, she says she likes Brain better.
- Didn't Think This Through: Arthur has an Imagine Spot of Brain building a time machine that only goes backward rather than forwards. Cue them ending up in the time of the dinosaurs, far away from home. Arthur snaps out of it quickly.
- Green-Eyed Monster: Arthur despite himself becomes jealous at how much his family likes Brain.
- Hidden Depths: It's revealed Brain is also a good basketball player, model plane enthusiast, and storyteller.
- You Never Did That for Me: A variant; Arthur gets insulted when D.W. would rather read with Brain than with him. D.W. bluntly says that Brain reads faster than he does.
