The information of the new justice of Royal Wood is made speak by everyone. Of their hope they did.
The next morning in Johnson's class. All the students ask Ivan about his transformation into a monster.
Marinette feels responsible because of the presence of tons of Stoneheart in the city.
"Tikki, I don't think I was the right girl to be Ladybug. I failed to capture Akuma. If the Stonehearts become active, the city will be in danger because of me."
"Everyone makes mistakes. I'm sure next time you'll be successful." Tikki says to reassure Marinette.
"If you say." She arrives at the school and sees the students talking to Ivan because of the events of yesterday.
"Ivan, that was really crazy." Rusty told Ivan.
"You almost flattened yourself with your fists." Chandler tells Ivan.
"I'm sorry. I don't understand. I suddenly felt anger wash over me and the next minute I turned into this monster…." These are the memories of Ivan.
The teacher arrived in the classroom to begin the lesson.
"Ok, class let's start the lesson. Open your book to page 12."
Students open their books on page 12.
During this time. The Akuma has multiplied into millions and infects every one of the inhabitants of Royal Wood, the victims turn into a copy of Stoneheart.
The copies are inactive.
The scene changes to Royal Wood Street. Adrien Agreste runs towards the school.
"I don't understand, why do you want to go to school? You can stay home and relax." Plagg says.
"You don't understand Plagg. I want to be an ordinary boy like kids my age for once. That's why." Adrien says.
The blond boy arrived in front of Royal Wood Elementary School. A black limo has arrived and Gabriel's secretary gets out.
"Adrien, you know your dad doesn't want you to go to school," Nathalie said.
"Please, Nathalie. I just wanna be a regular boy for once."
"Ok but what do I have to say to your father?"
"Just tell him you couldn't stop me." Adrien said before entering the classroom.
Ivan couldn't help but research the paper he had in hand.
(Mylène…) He looked at the girl in the row in front of him.
At the break, everyone is talking. Ivan is in his corner and he is pensive.
Lincoln, Clyde and Marinette see it, go see it.
"How are you, Ivan?"
"Yes. It's just because of this morning."
"Yeah, this morning Chandler made you angry? Just to find out, what was the source of this?" Marinette asks.
"I wrote this poem song for Mylène but Chandler is making fun of me and it made me angry."
"Are you in love with Mylène?"
"Yes.
"I think it would be best if you tell Mylène your poem." Lincoln suggests to Ivan.
"Are you sure?"
"Yes, in Love Boat it works."
"Ok I'll try. "
There are still 30 minutes left before the second period begins and Ivan decides to sing his song.
He waits for the girl at his locker, Mylène is surprised to see him.
"Hi Ivan."
"Mylène, I wrote a song for you." Ivan begins to sing it loudly.
The girl covers her ears and runs away. This makes Ivan sad and he gives back negative energy.
"This is the emotion I need. StoneHeart!" Hawk Moth sends his Akuma.
Ivan transforms into Stoneheart again. Stoneheart copies are now active.
The stone monster enters the classroom destroying the wall. The manager in the hall sees this.
"Frankly, the wall again? Even if you've become a monster, could you at least check if the door is unlocked?"
"Mylène !" The stone creature grabs the girl and leaves.
Stoneheart copies follow the original. Lincoln and Adrien come out of the classroom.
"As, we have to stop him."
"Yes."
"Let's Play!" Lincoln turns into the Ace of King and goes to confront the monsters.
Cat Noir joins him.
"Hey, Stoneheart! Ready for round 2?" Chat Noir says to summon the stone monsters.
"Catch them!"
The stone monsters charge the two heroes. Ace of King and Black Cat are doing their best to fight against this countless enemy.
The two heroes dodge them and go on the main enemy.
Cat Noir attacks him with his stick and Ace of King attacks him by throwing the poker cards.
Their attack makes Stoneheart grow taller and stronger.
Meanwhile, Marinette sees the damage Stoneheart has done to Royal Wood.
"Marinette, Ace and Cat need you to stop Stoneheart."
"But Tikki, if I fail again? It's not Royal Wood who will be in danger, it's the world." Marinette has doubts.
"Marinette everyone deserves a second time. I'm sure you'll do it. Trust yourself."
Marinette takes her courage and all her determination to save the girl.
"Tikki, spot on!"
The Kwami Ladybug vacuums into the earring and Marinette transforms into Ladybug. She joins Ace and Chat in the town center of Royal Wood.
StoneHeart still holds Mylène in hand. "Mylène, you will be mine forever."
"Ivan, this isn't you. You're out of control."
"If I am against it !"
Chat Noir and Ace de Roi attack the stone monster which becomes even bigger.
The three heroes are in front of the villain. Suddenly he is motionless and black butterflies come out of his mouth, taking the shape of a face.
"Who is he?"
{Ladybug! Black cat ! Ace of King! Give me your Miraculous. Because of you, the lives of the people of Royal Wood are in danger, so I order you to surrender!}
"Rather, it is you who put the people of Royal Wood. You created the monster that put their life in danger. When we get there." She takes her yoyo to capture the horde of black insects. "… To protect them !"
{No!}
Each of the dark butterflies is captured, the face disappears and Ladybug releases a horde of white butterflies.
"A Tour, Stoneheart! Lucky Charme!" His special power spawns a parachute. "How can I serve this?"
"While you're thinking. I'll take care of the copies. Full Deck !" His power is called Strong Suit.
The superhero version of Lynn. Strong Suit attacks copies of Stoneheart.
"Chat the ground!"
"Understood my lady. Cataclysm!" Cat Noir's hand is concentrated with destructive energy. He hits the ground, which crumbles under the golem's foot.
"Ahhh !"
Both falling. Ladybug uses the parachute as a trampoline to jump and save Mylène. StoneHeart is passed out.
"Strong Suit, do you think you're strong enough to open his big hand?"
"Easy." Strong Suit jumps, lands on the stone monster and opens his hand and picks up the paper ball.
The ladybug girl comes down and tears the paper.
"It's over for you, little Akuma." She captures him and releases him as a White butterfly.
Then she uses her Miraculous Ladybug. Millions of ladybugs repair all the damage done by Stoneheart.
"To find!"
The three heroes managed to stop the villain. Marinette now has more self-confidence.
In the distance. An old man in a Hawaiian shirt watches the scene next to a turtle-like creature.
"You made the right choice to entrust his Miraculous to his three youngsters. Royal Wood now has protectors." Wayzz said.
"Yes, I am sure that one day they will be able to recover the butterfly miraculously."