All the youth of Mewni gather at the ancient Monster Temple to celebrate a new era of Monsters and Mewmans living together in peace, until guests start disappearing!
Tropes:
- Accidental Dance Craze: Marco's "sword-hand dance" has apparently become popular among the youth of Mewni.
- Armor-Piercing Question: Star brings up the Double Standard applied to the arrest of the loitering monsters by asking the knight why won't she deal with the non-monster troublemakers. She has no answer. All she does is let the monsters go out of complacency.
- Artificial Limbs: Aside from his mechanical legs, Rich Pigeon also wields a mechanical pair of arms. He uses them to do the sword hand dance.
- The Bad Guy Wins: Mina captures the monsters, fights Star, and then the cops come, and tensions are higher between monsters and Mewmans, which is exactly what Mina wants.
- Bait-and-Switch:
- During a tense moment at the party, Rock Johansen breaks the silence, saying "If no one else is gonna say anything, I will!" Turns out he wanted to break the ice by complementing one of the monster guest's pre-ripped jeans.
- A slime monster appears to be offering to dance with Princess Spider-Bite, but she's grossed out... because she thinks he's coming onto her. Then it turns out his slime has healing properties, and he was offering to heal her spider-bite.
- Bait-and-Switch Boss: In spades. At first, it looks like Miss Heinous is the opponent the heroes have to fight due to spying on them, and when monsters are disappearing, Mina Loveberry shows up in the dungeon, and it turns out she was the one kidnapping the monsters. Then Miss Heinous comes crashing down on her just when it looks like a fight with Mina was going to ensue, and then Mina rises again and she's the main threat they have to face.
- Black Speech: Uttered by Tom to summon a casket of black stone to imprison Mina
- Brick Joke: Eclipsa isn't the only one who mistakes Marco's karate poses for some kind of "sword-hand dance".
- The Bus Came Back: Many past characters return, some vital in the plot.
- The princes and princesses from the Silver Bell Ball appear again.
- The alternative monsters Star befriended in "Raid the Cave" are guests at the party.
- Pony Head's friend from the Bounce Lounge, Johnny Blowhole, brings back the photo booth.
- Roy, the Goblin Dogs vendor is supplying his food to the party.
- Mina Loveberry reappears in the basement, and has a vital role in the climax.
- Miss Heinous, Gemini and Rasticore try to kill Marco again, and the headmistress is in for a major surprise.
- In her fight with Mina, Star uses the Spider With a Top Hat spell again.
- Rhombulus, Lady Whosits and other knights show up at the end to arrest the Monsters (but not the Mewmans) for the ruckus at the party.
- The Cavalry Arrives Late: Rhombulus and the knights arrive to defuse the situation, but Heinous is long gone and Mina manages to escape. It also kinda counts as Cavalry Betrayal because Star is the one who gets in trouble, and the monster kids get mistreated.
- Childhood Home Rediscovery: The temple Star is throwing her monster/mewman party in was Miss Heinous' nursery, and revealed that she is a member of the Butterfly family, namely, Queen Eclipsa's daughter.
- Conflict Killer: The whole conflict between Miss Heinous and the heroes is smashed when Mina rises and shows how powerful she is.
- Continuity Nod:
- Star wears her Song Day outfit from "Face the Music", while Marco wears the suit he wore for his date with Jackie in "Bon Bon the Birthday Clown".
- Pony Head and Johnny Blowhole bring the old photo booth from The Bounce Lounge to Star's party.
- The alternative monsters from "Raid the Cave" are guests at Star's party.
- The Spider with a Top Hat spell returns in the fight against Mina, to no effect.
- Marco's karate stance is once again mistaken for a "sword hand dance".
- Curb Stomp Cushion: Star, Marco, and Tom Vs. Mina. The result is that Mina manages to hold her own with barely a scratch. Although Star's double rainbow fist punch, Marco throwing books, and Tom's magic coffin trap manage to do some damage but not even those seem to slow her down even a bit.
- Darker and Edgier: In her first appearance, Mina's craziness was mostly Played for Laughs. Here, it's shown that her lack of sanity and shameless bigotry makes her an extremely dangerous opponent who is impossible to reason with.
- Despair Event Horizon: After the party is ruined, the monster kids lose any hope of ever being treated as equals in Mewni. Likewise, Star feels that with tensions between monsters and Mewmans having worsened, she can never accomplish her dream of having an integrated Mewni society.
- Did You Just Punch Out Cthulhu?: Mina gave even the Demon Prince of The Underworld a run for his money, easily withstanding his own infernal magic.
- Double Standard: A racial one. When the knights show up at the end to arrest the guests for loitering outside the temple, they intend to get only the monster ones for questioning, while not just ignoring the Mewman troublemakers, but giving them shock blankets and hot cocoa. Lampshaded by Star, and then some.
- Downer Ending: Star's party ends in disaster, and put a serious crimp in her hopes for peace between Mewmans and Monsters. Plus, the events of the night have raised a lot of questions about her family's history.
- Face–Heel Turn: While Mina was rather reckless and wasn't very nice from the start, she becomes a full blown villain here, bent on keeping the status quo of Mewman superiority over monsters. In fact, what she did was borderline terrorism.
- Fantastic Racism: The Monsters and Mewmans.
- Glamour Failure: When Heinous realizes her true heritage, she regains monster features that were evidently disguised by magic.
- Go Mad from the Revelation: Heinous, upon realizing her true heritage, has a Villainous BSoD. At the end of the episode, she forsakes her name for her true one, Meteora Butterfly.
- Green-Eyed Monster:
- Turns out Pony still feels a bit of rivalry with Marco over the position of Star's best friend. As she made a point of rubbing it in his face that Star called her the best.
- Marco is visibly upset at any displays of affection between Star and Tom, and is unusually cold to Tom as a result of his jealousy.
- Healing Hands: Turns out Slime's slime helps Princess Spider-Bite get rid of her titular condition.
- Helicopter Hair: Mina makes her escape by jumping out of a window and flying away by spinning her hair.
- Hidden Depths: Who expected Miss Heinous to be a fan of heavy metal and headbanging?
- Hope Spot: At first the party is going great as the Mewmans and Monsters are getting along. Then Mina starts kidnapping the monsters...
- Hypocritical Humor: Mina complains about Star interrupting her... when Mina is barely letting Star get a word in edgeways.
- I Am Who?: Miss Heinous discovers that she is Meteora Butterfly, the half-monster daughter of Eclipsa.
- I'll Never Tell You What I'm Telling You!: Subverted. Rhombulus insists the true nature of the temple is classified, but Star says he doesn't even know. He only blurts it out just to prove he does, but his snake hands manage to get him to keep his mouth shut.
- I'm Okay!: Slime says this after he and Princess Spider-Bite fall through a secret passage, and she lands on top of him.
- It's All About Me: Downplayed, but Tom is clearly annoyed that Star is more concerned over making sure the Mewmans and monsters get along then spending time with him.
- I Was Just Joking: About when Marco accidentally broke Rich Pigeon's leg:
- "Just Joking" Justification: Rich Pigeon shoots a Nightmare Face at Marco and tells him "grudges last forever", in reference to his broken leg. Turns out he was just joking.
- Karma Houdini: Mina captures innocent monsters, cause a lot of destruction at the party and tensions between Mewmans and Monsters and manages to escape unpunished.
- Knight Templar: Mina, going so far as to kidnap monster kids.
- "Knock Knock" Joke: When Star and Marco go check the situation in the basement, she leaves Pony Head in charge of breaking tensions by telling jokes to the guests. We see her telling a knock knock joke, only for it to be "answered" by Mina crashing through the ground.
- Locked Out of the Loop: Marco feels like this as The Reveal about Heinous' nature ensues, demanding that someone fill them in already.
- Luck-Based Search Technique: As Slime reclines against a wall, he crashes through it, ending up in a secret passage to the basement, where he and Princess Spider-Bite are captured by Mina.
- Luke, I Am Your Father: Turns out Miss Heinous is Star's distant relative. Later it's revealed that she's the last descendant of the original Butterfly royal family.
- Mundane Made Awesome: Star decorates the hall by jumping around, reaching a wall to put a birthday hat in the statue. She then jumps into her boots to wear them.
- Mundane Utility: Tom's fire powers come in handy for quite a few mundane situations, some of it accidental.
- When Star gets her tongue stuck in the punch bowl she froze, Tom simply uses his fire powers to melt the ice block.
- Also, when he goes down the basement to look for Star, he summons a single flame to act as his light source.
- At the end, he uses fire to burn the punch cup for Star to drink it,
- Nice Job Breaking It, Hero: Hero might be a stretch here, but Mina, a celebrated Mewni hero, is so Axe-Crazy that she can't comprehend the idea of there being such a thing as a "good" monster and kidnaps several monster party-goers. This causes tension between the otherwise amicable Mewni and Monster youths; her rampage alerts the police guards who show up and arrest the Monsters for "loitering" while handing out hot chocolate and blankets to the Mewmans (and Marco). This in turns severely damages Star's efforts and leaves the Monsters dejected, even after Star uses her authority as princess to convince the guards to let the Monsters go. Similarly, if she hadn't kidnapped those Monster youths, Heinous' linage as Eclipsa's daughter and her status as a Half-Human Hybrid wouldn't have been revealed and in turn cause her to remember her identity as Meteora. Thus, Mina is personally responsible for awakening what she herself called "the most dangerous monster in the history of Mewni".
- Nightmare Face: Pigeon does this when joking to Marco that "grudges last forever". It scares Marco a bit.
- Noodle Incident: It seems Rock Johanssen got into a boating accident, resulting in the spikes protruding from his arms.
- No-Sell: In her hulked-out form, Mina Loveberry is tough enough to shrug off Star's strongest spell, Spider-with-a-Top-Hat Blast.
- Not Helping Your Case: Tom tries to convince Star that her party wasn't a bust, but accidentally reminds her of everything that went wrong.
- Nothing Is the Same Anymore: Not only is Heinous revealed to be a member of the Butterfly family, but tensions between Mewmans and monsters are higher than ever, and Star is left with so many questions about her family's heritage.
- One-Winged Angel: Mina activates a hulked-out form which makes her not only stronger, but can No-Sell all of the heroes' attacks.
- Poor Communication Kills: Star could've at least mitigated things if she had told Rhombulus that Mina was the one who caused trouble.
- The Reveal: Miss Heinous' real name is Meteora Butterfly, and is Eclipsa's daughter.
- Save the Villain: Once Star discovers Miss Heinous' true origins and her backstory, she stops Mina from trying to kill the former headmistress.
- Sequel Hook: Rhombulus says the Monster Temple has some major importance (apparently besides Meteora's nursery), but won't say what.
- Ship Tease:
- Marco accepts Kelly's offer to do the sword hand dance with her.
- Slime and Princess Spider-Bite's interactions also count as Ship Tease.
- Marco's reactions to displays of Star and Tom's relationship and his unusually cold attitude towards Tom imply some jealousy on his part.
- Shout-Out:
- To Sailor Moon, fittingly; one of Mina's books at her camp is "Secret Tuxedo", a reference to Tuxedo Mask, Sailor Moon's love interest.
- Another book is called Thirty Shades of Magic, a reference to the novel Fifty Shades of Grey.
- Sympathy for the Devil: Even Star feels rather sorry for Miss Heinous, the very woman she feared and hated from the first season.
- That Woman Is Dead: Inverted. Upon becoming aware of her true origins, Miss Heinous forsakes her name and now goes by her true name of Meteora Butterfly.Gemini: Ooh, there's too much heat out there. We should get going, Miss Heinous.
Heinous/Meteora: That's not my name.
Gemini: I'm... sorry?
Meteora: My name is Meteora. - Tired of Running: When Marco faces Heinous again, he says he's done with running from her and prepares to take her on.
- Tongue on the Flagpole: Star accidentally freezes the punch bowl in a block of ice and her tongue gets stuck to it.
- Villain: Exit, Stage Left: Mina leaves just as the cops arrive. Miss Heinous gets away too, but her car gets confiscated.
- Wham Episode: Heinous is actually Eclipsa's daughter, her real name is Meteora Butterfly, and Mina has been waiting for her return for decades.
- Wham Line:
- Star discovers who's been abducting the monster guests... and runs into a familiar face in the process.Star: Mina Loveberry?!
Mina: Mud sister?! - Later:Mina: I knew you'd be back here one day... Meteora!
Gemini: I beg your pardon! This is Miss Heinous, the honorable headmistress of St. Olga's School for Wayward Princesses!
Miss Heinous: No, Meteora. That is my name. At least, it was my name a long, long time ago. - Then:Mina: Don't you ding-dongs know anything? She's [Eclipsa] her [Heinous/Meteora's] momma!Marco: Eclipsa is Heinous' mother?! But how?! She's hundreds of years old! Besides, that would make Heinous... a princess!Star: (eyes widening in realization) It... means she's a Butterfly...Mina: It means, she's a monster!
- Star discovers who's been abducting the monster guests... and runs into a familiar face in the process.
- Wham Shot: The nursery where Miss Heinous spent her early childhood, which includes dolls of her very familiar parents (Eclipsa and her monster lover), a crib labeled with her real name (Meteora), and a mural of Eclipsa holding her as a baby.
- The Worf Effect: Mina takes out the demon Tom, who is at full strength with his demon powers. She also shrugs off the Spider-with-a-Top-Hat Blast, stated by Star to be her strongest spell, like it is nothing.
