Sometimes, a really big problem requires many small solutions.
"You can't do this alone, but it's only because you're lacking a good deputy! I'm giving you the power to create your own sentimonster to assist you — this will allow you to be everywhere at once and force everyone to agree with you! All I ask in return are Ladybug and Cat Noir's Miraculous…"
—Shadow Moth
Ivan and Mylène lead Miss Bustier's class, and eventually a large amount of civilians, on a protest against Project Oxygen, which will implicate chopping down trees. The overwhelmed Mayor Bourgeois finds himself re-akumatized into Malediktator... with a new sentimonster that carries small but multiple nasty problems with it. Can Mylène, as Polymouse, muster the courage to help Ladybug dispel the chaos?
Tropes:
- Absurd Phobia: Among many more rational fears, Mylène suffers from fear of badges.
- Adults Are Useless: Zig-Zagged. On the one hand Roger tries to be diplomatic with the two protestors, getting this reaction from André who orders him to do his job. On the other, Caline immediately rallies behind her students, ordering Roger (a fellow parent) to turn the two over to her custody (1. because it's a school day, so they are technically her responsibility, 2. because he shouldn't be arresting kids for protesting). She then gives the class a 'practical civics lesson' by escorting them to the park personally to help Mylène and Ivan's protest. The other parents (Fred, Tom and Sabine) all show up to back their children up, and even Roger backs the protest.
- An Aesop: Big problems aren't solved with big, easy answers; they are solved with small, multiple solutions working towards a common good.
- As You Know: Mylène explains to Marinette that she and Ivan have been protesting the construction of the Oxygen Tower for months on end. Marinette claims she didn't know of it because she was busy with other things.
- Bait-and-Switch:
- When she learns that Ivan and Mylène are at the square protesting the construction program, Miss Bustier tells Officer Raincomprix to bring them back to the school… so she and the other students and her class can join together and rally as a bigger group to protest the project.
- Done to Adrien when he is told he is filming an advert for a new air freshener, when in reality he was filming a commercial for the new "Oxygen" tower. Seeing the finished commercial causes Adrien to publicly declare his disdain for the project, inadvertently causing a PR issue for his father, who financed the project.
- Bittersweet Ending: The gang managed to stop Project Oxygen, but in the final scene of the episode, Gabriel reprimands Adrien for taking a stand and siding with the protesters against his project. Adrien tries to explain to his father that it wasn't his intention but Gabriel refuses to listen to him and orders his son to go to his room. Adrien sadly obeys him and accepts his punishment.
- Brain with a Manual Control: Malediktator's Sentimonster Mega Leech has the ability to divide Malediktator into countless tiny clones of himself, who can then control people by entering through their ears and dictating their actions through a podium inside their heads.
- The Cameo: Wayhem, Adrien's totally-not-creepy fan friend, appears to support his idol in stopping the park's deforestation.
- The Cavalry: Because Mega Leech's ability also divides the akuma and amok, Ladybug has to grab Polymouse (Mouse), Pegasus (Horse), Vesperia (Bee), Ryuko (Dragon), and Carapace (Turtle) to join her and Cat Noir in the fight. Polymouse is able to divide herself to take out the many clones of Malediktator and release their akuma/amok pair, Pegasus teleports Vesperia on top of Mega Leech to paralyze it and prevent more clones from being spawned, Ryuko uses her wind power to gather the akuma/amok copies into a single swarm, and finally Carapace uses his Shelter to contain them all in one spot for Ladybug to purify. This gives the episode the second highest superpower count at nine (Shadow Moth having two Miraculous simultaneously), with "Miracle Queen" being the highest at eleven.
- Continuity Nod: Mayor mentions his previous project, Space Dumpster Program.
- Cool Teacher: After learning about Mylène and Ivan getting in trouble for protesting, Miss Bustier not only orders their release but rallies the rest of her students to participate in the protest. And she doesn't hesitate to stand up to the mayor.
- Cruel to Be Kind: Marinette pretends to be brainwashed in order to scare away Mylène so she can transform in private and save everyone. Tikki gives her a Disapproving Look for it, but she protests that she had no other choice.
- Dismantled MacGuffin: Mega Leech not only divides Malediktator into thousands of copies, he does the same to the akuma and amok in Malediktator's sash. This means the heroes have to disable every single copy in order to defeat the sentimonster.
- Distracted by the Sexy: At first, Marinette fails to properly protest against the destruction of the park because of how cute Adrien looks in the Project Oxygen ad. She eventually gets a grip on herself... only for Adrien to hold her hand while forming a Human Shield to protect the trees, sending her back into la-la land.
- The Ditherer: André Bourgeois is in conflict as to whether he should continue the destruction of the park trees to create the Oxygen Tower or cancel the project to make peace with the protestors. He eventually chooses the latter.
- Evil Chancellor: Shadow Moth frames himself as this to André saying that this time he will have a strong advisor to help ensure he can control everyone everywhere, with his very own sentimonster to aid him. André even compliments him on his political strategy.
- Explain, Explain... Oh, Crap!: Marinette uses the video commercial the Mayor shows to confirm that the building of the Oxygen tower will cause more pollution in the long run due to using the recycled air as fragranced perfume, the bottles of which are not recyclable. André agrees with her summary before realising what he just confirmed, live on air.
- Five-Second Foreshadowing: Ivan gives Mylène the pet name of his little mouse, indicating that she'll become the holder of the Mouse miraculous this episode.
- Freeze-Frame Bonus: When Wayhem shows up with a group of fans, one of them has a t-shirt with the Cat Miraculous symbol.
- Funny Background Event: When all the highschoolers hold hands to form a Human Shield to protect the trees and are loudly protesting, Marinette, whose hand was taken by Adrien, is gazing adoringly at him instead.
- Go to Your Room!: At the end of the episode, Gabriel orders Adrien to go to his room for protesting against the Oxygen project, as he claims it was a stand against him. Adrien tried to explain that was not his intention, but Gabriel refused to listen.
- Green Aesop: The episode seems to be criticizing "greenwashing" as the Oxygen Project claims to be environmentally friendly but requires trees to be cut down, and will sell the fresh air to people rather than give it for free.
- Heroic Sacrifice: Ivan pushes his girlfriend away just seconds before she's taken over by a micro-Malediktator.
- Improbable Weapon User: Polymouse uses the ice skating shoe Ladybug gives her to defeat the micro-Maledictators, tying it to her jump rope as a bladed whip/flail.
- I'm Standing Right Here: Done by proxy. When Marinette is gushing over how cute Adrien looks in the ad, Alya grins and nudges her head to the left, which reminds her that Adrien is standing not three feet away from her.
- Just a Kid: The reason Officer Roger didn't want to arrest Mylène and Ivan. Also, when Marinette and her classmates protest André's Oxygen Tower, André resorts to arguing that they're just kids who don't know what they're talking about to try to get them to go away. It falls flat when several of their parents side with them. Marinette's parents even stating again that it's wrong to try to use police since the students are just innocent kids.
- Literal Metaphor: Sometimes, as Mylène spends the first half of the episode explaining, a problem needs many small solutions. Polymouse, as a hero with the power to split into a horde of tiny duplicates, is quite literally many small solutions to the problem of Mega Leech.
- Meaningful Echo: Mylène says that to fix the environment, they need "to have a whole lot of little solutions happening all at once" rather than one big project. Ladybug later echoes this sentiment when Malediktator replicates himself.
- Mouthscreen: A closeup of Gabriel's mouth silencing Adrien trying to defend his actions against his father's project and ordering his son to go to his room.
- Paying for Air: Mayor Bourgeois' Project Oxygen is a tower that purifies polluted air and then stores it so it can be later sold in plastic bottles. No wonder that Ivan and Mylène are protesting against it.
- Plot Parallel: In the first part of the episode, Mylène is making a point that environmental problems need many small solutions — in the second part, she becomes Polymouse and is many small solutions.
- Power Dyes Your Hair: Mylène's hair goes from blonde to pink when she transforms into Polymouse.
- The Real Heroes: Alya uses her superhero blog to promote her class protesting against Project Oxygen ("Just because there aren't any supervillains attacking Paris right now doesn't mean there's nothing super going on!") and later Ladybug directly compares Mylène's actions to being a hero.Ladybug: The objects that help you get over your fears are just like the Miraculous and you fight everyday to defend a cause without anyone noticing. That's just like having a secret identity. Truth is, you already are a superheroine.
- Refusal of the Call: At first, Ladybug doesn't even finish offering her Miraculous before Mylène turns her down saying she's too cowardly to be a superhero. Ladybug manages to convince her otherwise.
- Rule of Funny: Polymouse enters Cat Noir's head through his cat ear.
- Self-Duplication: Shadow Moth grants Malediktator the Sentimonster Mega Leech, which can create tiny clones of him to do his bidding. In response, Ladybug recruits Mylène to be the Mouse holder, becoming Polymouse, who has the power of multiplication, fighting the micro-Malediktators while Ladybug and co. focus on Mega Leech.
- Shout-Out: Cutting down trees and selling bottled air is reminiscent of both the movie version of The Lorax and Spaceballs.
- Survival Mantra: The always scared Mylène has one for getting the courage to stand by her convictions in the opening scene. She echoes it as Polymouse when told she has to take a Leap of Faith into an air turbine, trusting that the turbine will blow her up into the air once she multiplies.Mylène: I'm not scared, I can do this. I'm not scared, I can do this.
- The Tag: The story ends with the Mayor deciding to spare the trees and create a new project that promises the development of an all natural Mega-Tree. The last scene features Adrien being chastised by his abusive father for siding with the protestors and is told to go to his room. As he does, Gabriel gives an ominous look while clutching his ring.
- Take That!: Project Oxygen — an alleged "environmentally-friendly" corporate tower that filters the air and sells it to the populace — comes across as a critique of corporate greenwashing. Mayor Bourgeois markets Project Oxygen as an environmentally friendly addition to Paris' skyline that will help with Paris' growing smog problem and that replacing the park and its trees is a necessary sacrifice. Mylène and Ivan protest it because they see that Project Oxygen is much more sinister than it markets itself to be and that all it will do is escalate environmental degradation, as well as create a new problem via the plastic bottles used to distribute the filtered air. It's also implied that while Project Oxygen's construction is funded by tax-money, the filtered air it produces will be sold to the populace as a commodity, meaning that the Mayor is using tax-dollars to line his own pockets by making his own constituents pay for air.
- Team Shot: Ladybug and all the heroes she gathers to defeat Mega Leech get one. Lampshaded by Cat Noir as he hurries to join them.Cat Noir: Group pose!
- Unwitting Pawn: Adrien was smeckledorfed into participating in a commercial that advocated for the Oxygen Tower's creation; he initially believed it was a regular perfume commercial.
- Voices Are Mental: Anyone who's brainwashed by a micro-Malediktator speaks with his voice. Luckily, Mylène didn't notice that Marinette was contradicting this by still speaking with her own voice when she pretended to be a victim.
- What the Hell, Hero?: Ladybug doesn't hesitate to scold Mullo for purposely scaring Mylène upon meeting her.Ladybyg: Mullo, that's not nice!
