Star's search for her mom takes her to the home of the Pie Folk, where she must outwit them in order to reunite her family.
Tropes:
- Ambiguous Syntax: When the Pie King puts Star, River, and Marco up for auction, he mentions they would be good for "making pies". Star and Marco argue about whether he meant forcing them to make pies or making pies out of them.
- Big Damn Heroes: Foolduke shows up with her hot air balloon to rescue the Butterfly family and Marco from the Pie Folk.
- Blatant Lies: The Pie King claims that the amnesiac Moon is free to choose whether she wants to stay or leave. But when she decides she wants to leave with Star, he refuses to let that happen.
- Brutal Honesty: Star declines to have River help her and Marco get to Moon, on the grounds that he always messes things up.Star: Uh, is that mean? I know it sounds mean.
- Burning the Ships: River scuttles the ship that brought them to Pie Island so the Pie Folk wouldn't steal it.
- Con Artist: This is the Pie Folk's hat. They con and steal from everyone, even each other.
- Continuity Nod: According to The Magic Book of Spells, the Magic High Council raised Festivia, and she was closest to Hekapoo. The Pie of Truth specifically shows Hekapoo holding a young Festivia.
- Crocodile Tears: River attempts to gain the Pie Folk's sympathy with fake tears... created by having crabs pinch his legs.
- Dressing as the Enemy: Star and Marco decide to steal disguises from two chef mooks that River beat up so that they can infiltrate the mine and see how much Moon remembers. Star later ditches her disguise and decides to go all out on the workers.
- Hope Spot: It looks like Star and company are making a clean getaway with Queen Moon, but then Cloudy starts falling because she's sick from the monkey feeding her too many pies.
- Lamarck Was Right: It seems that Moon inherited the style of pie crust she makes from distant Pie Folk ancestors that she'd never knew about (it's apparently supposed to be a moth, not a butterfly).
- Lava Is Boiling Kool-Aid: Literally, in this case. The "lava" in the volcano is lukewarm tomato juice.
- Literal-Minded: When River calls Moon "Moon-pie", she angrily retorts that she is "not a pie".
- Maniac Monkeys: Foolduke's pet monkey, who keeps stealing from Marco.
- Mugged for Disguise: After River beats up a couple of Pie Folk chefs, Star assumes he did so for this reason. River goes along with it.
- Non-Indicative Name: Subverted with the Butterfly Pie Lullaby. At first glance, the lyrics are all about rabbits, not butterflies, but they're actually a metaphor for instructions on how to make the butterfly (or rather, moth) shaped decoration on the pie crust. The song still fits Non-Appearing Title, however.
- Paper-Thin Disguise: Star, River and Marco's disguises don't fool the Pie Folk, since Star's and River's aren't the right style, and Marco's is just a slice of pie.
- Planet of Hats: The Pie Folk, aside from being pie makers, are also notorious scam artists. Nearly everyone they meet at Pie Island is trying to rip them off.
- The Reveal:
- Foolduke's family are Pie Folk, and she isn't proud of that fact.
- The baby that became Queen Festivia was a Pie Folk orphan, meaning that the Butterfly line from then on, including Moon and Star, are technically Pie Folk. Star does not believe it for a bit, because the person telling her this is a chronic liar.
- Running Gag: Foolduke's Monkey repeatedly messing with Marco, ranging from stealing his wallet and shoes to threatening to let him fall into what Marco thinks is lava.
- Screw This, I'm Outta Here: This is how the Pie Folk man who offered to guard the heroes' ship reacts when River sinks it."A'ight. I'm out." [walks away]
- Something Only They Would Say: Star singing a lullaby that Moon used to sing for her jogs Moon's memory.
- Tempting Fate: Foolduke says Ruberiot lost everything they had except for the balloon they used to come to Pie Island. Ruberiot is then shown losing that balloon.
- Tomato in the Mirror: Star doesn't react well to finding out she's related to a bunch of piemakers and scam artists, and she suspects it has to be a lie. But, how else could Moon have possibly known that style of pie crust if that's what the Pie Folk have been using for hundreds of years?
- Villains Never Lie: Star accuses the Pie Folk leader of lying to keep her mother prisoner among the Pie Folk, ironically by narrating from The Pie of Truth. He retorts that Moon found them, and how come Moon fits in so well with them? (If the Pie King is to be believed that is?)
- Whammy Bid: The disguised Foolduke makes a bid of "45 billion, 710 million, 412 thousand, 242... pennies" for Star, Marco and River.
- White Sheep:
- Foolduke is one of the Pie Folk, but is not a Con Artist like the others (and is deeply annoyed by how her parents keep cheating Ruberiot).
- In a case of Nurture over Nature, Festivia and all her descendants are this for the Pie Folk, as despite being Pie Folk, none of them were con-artists. The only exception seemingly being Crescenta, Festivia's 2nd-born daughter, who was manipulative and vile like the Pie Folk.
- Wham Episode: Star and co. finally find Moon, but she isn't quite ready to leave Pie Island yet. She's lost most of her memory after spending so long in the Realm of Magic. But why does she feel more at home on Pie Island than on Mewni? Remember Festivia the Fun, the peasant girl that King Shastacan had Meteora swapped out with? (If the Pie King is to be believed) She was born a Pie Folk, left behind by accident, taken in by the Magical High Commission, and reared to succeed Eclipsa in Meteora's place. This means every Butterfly monarch after Eclipsa is not only not of royal blood, but (possibly) isn't even Mewman, and this includes Star herself.
- Wretched Hive: Pie Island is full of thieves, liars and scam artists who will prey on you and take your valuables, or make you do things you will regret.
