Marinette is on the balcony of her house, talking to Tikki about Adrien. Whenever Marinette tries to talk to him, she can't say anything. Tikki suggests talking to him on her cellphone, and Marinette calls Alya to ask for Adrien's number.
Meanwhile, at the Place des Vosges, a statueis about to be revealed. Sculptor Théo Barbotis congratulated by the mayor for putting the effort into making the statue. Théo wishes to meet Ladybug and get her to autograph a picture of her.
Inside Marinette's room, Alya has prepared a speech for Marinette to read to Adrien over the phone to invite him to the movies. Marinette protests, saying that she sounds awkward and unnatural when she reads out loud. Alya replies that Marinette should memorize the text. Before Marinette can back out, Alya presses the "call" button.
Marinette dances around with the phone in her hand before she is directed to Adrien's voicemail. He is currently at fencing practice, as seen by Adrien's schedule on the calendar attached to Marinette's ceiling. Alya tells her to leave a message. Panicked, Marinette leaves an impromptu voicemail and throws it on her chaise lounge back to Alya. She then accidentally records herself confessing her crush since she never ended the call. They try to delete the message, but Adrien's phonesaves it. To save her dignity, Marinette and Alya hurry to the school to delete the message from Adrien's phone before fencing practice ends.
Meanwhile, Adrien takes a break from practice to get some water. Hidden away in his locker, Plagg tells him he has a new voicemail on this phone from an unknown sender. When Adrien goes to check his messages, he notices that it is nearly 2:00 and that he'll be late to the statue reveal. He quickly transforms into Cat Noir.
Just as they leave the bakery, Marinette and Alya notice Cat Noir jumping over the rooftops and landing in front of the statue at the Place des Vosges. Only then do they remember that the statue reveal was supposed to be today. Alya stays in the park to take pictures of the ceremony for the Ladyblog while Marinette runs ahead to the school to erase the voicemail, hoping to return in time as Ladybug.
Théo is disappointed that Ladybug has not yet shown up to the ceremony, but Cat Noir assures him that she should be there soon. He goes as far as calling himself the leader of the duo. André thinks Ladybug might show up sooner if they start the ceremony without her, but Théo convinces him to wait a little longer.
Marinette sneaks into the boys' locker room and calls Adrien's cell phone to figure out which locker is his. Simultaneously, André ultimately starts the ceremony without Ladybug and unveils the statue, much to Théo's disappointment, and Marinette finds Adrien's locker. Tikki unlocks the door by phasing through it.
The statue ceremony ends and people leave. Cat Noir stays behind to thank André while Théo expresses his sadness at not being able to meet Ladybug. From Théo's words, Cat Noir realizes that Théo is in love with Ladybug. He becomes jealous, insinuating to Théo that he and Ladybug are already in a romantic relationship. Théo leaves angrily, wondering what Ladybug sees in Cat Noir.
Back at the school, fencing practice is over and the boys are returning to the locker room. Tikki is impatient to get to the statue reveal ceremony, but Marinette has been unable to delete the message from Adrien's phone; she cannot get past the pattern lock to open it. When the fencers enter the locker room, she hides behind the door, takes the phone, and sneaks out of the school just as Adrien returns. Adrien takes his bag from his locker and leaves, not realizing that his phone is missing.
In his studio, Théo rages about how Cat Noir does not take love seriously and how he, not Cat, deserves to be with Ladybug. Hawk Moth, sensing Théo's jealousy and anger sends out an akuma. The akuma lands on the photo of Ladybug, and Théo transforms into the supervillain Copycat. Hawk Moth promises that Théo can have Ladybug forever if he brings back Cat Noir's and Ladybug'sMiraculouses.
Back at home, Adrien cannot find his phone and thinks Plagg did something to it. Grabbing the house phone, he calls his cell phone, freaking Marinette out when he does. Thinking he left it at the gym, Adrien grabs Plagg and hurries out of the house. Meanwhile, Copycat wanders into the Louvre and steals the Mona Lisa as all the museum visitors look on, seeking to frame Cat Noir.In the car, Adrien hears of the theft and hurries into the school, transforming into Cat Noir and running off to the Louvre. His driverwaits outside the school.
Marinette is still trying to break into Adrien's phone, wearing ridiculous gear while doing so, when Alya calls from the Louvre, informing her about Cat Noir (Copycat) stealing the Mona Lisa. At first, Marinette is confused, thinking someone has robbed Cat Noir, but Alya clarifies. Marinette does not believe that Cat Noir would do such a thing. She transforms into Ladybug and goes to investigate.
At the Louvre, Cat Noir convinces the police to let him investigate the scene of the theft, telling them that the thief was an impostor. Under the guise of believing him, Roger Raincomprix tricks Cat Noir and locks him in the room. Roger refuses to let Ladybug see him when she arrives, telling her to leave this case to the professionals. Cat Noir uses his Cataclysm to escape, fighting off a squad of officers waiting in the entrance of the Louvre.
When Roger hears of Cat Noir's escape, he and Ladybug run inside, only to find the officers on the ground. Ladybug realizes that Cat Noir was holding back against the police. Ladybug leaves, letting the "professionals" take care of Cat Noir.
Outside, Cat Noir uses his staff to contact Ladybug's yo-yo, telling her he has to find the impostor and flees the police helicopters and squad cars. He disappears into an underground metro station and de-transforms into Adrien. Across the street at the Metro he entered is a pileup of police cars. Plagg suspects that the impostor is a new akuma victim and Adrien realizes it must be Théo, recognizing the lollipop stick that Copycat had planted in the Louvre.
Cat Noir arrives at Théo's studio and calls Ladybug, letting her know that he found Copycat's hideout. She asks where he is, but Cat Noir decides that—since this situation is his fault—he has to handle it alone so he doesn't tell her where he is before hanging up. Ladybug uses the tracking device in her yo-yo to find him.
Inside, Cat Noir finds a note in front of a Maneki-neko on top of a box from Copycat that says, "Cat's in the bag." The note turns out to be a trap, as the box springs open and catches him in a pair of shackles. He tries to use Cataclysm to break the chains, but Copycat appears from behind and forces his hand to touch a random plank of wood, wasting the Cataclysm. Copycat also steals Cat Noir's staff and poses as the real Cat, calling and informing Ladybug that he has captured the "fake". Cat Noir tries to tell her it's a trap, but Copycat hangs up before she can hear. He then reveals to Cat Noir his plan to win Ladybug's love from him and proceeds to taunt him.
Ladybug arrives just as Copycat is about to remove Cat Noir's Miraculous. He tells her that the akuma is inside the ring, encouraging her to take it off Cat Noir's finger just as the ring loses its second dot. The real Cat Noir begs Ladybug to ask the impostor about their relationship while using a nickname only the actual Cat Noir uses. Ladybug, realizing something is fishy, asks Copycat if he kept their secret promise. Not knowing that Ladybug and Cat Noir never made any promise, Copycat says he kept the secret, revealing himself as the fake. He says he loves Ladybug and insists that he would be much better for her than the real Cat Noir. Ladybug replies that while Cat Noir has his flaws, he has never lied to her. Cat Noir kicks Copycat off of him.
Copycat activates Cataclysm, claiming that if he can't have Ladybug, then no one will. Ladybug retorts that she belongs to no one and uses Lucky Charm, a spoon appearing. Cat Noir gets into a defensive stance. Copycat lunges to attack Ladybug, but she shields herself with Cat Noir's chains, using Copycat's Cataclysm to break them and free her partner. Freed, Cat Noir kicks Copycat into the opposite wall.
Cat Noir reveals that the Akuma is inside the photo in Copycat's pocket, but they have to hurry as his ring has lost another dot, while Copycat's countdown has only just begun. The two battle with Copycat, who is armed with both his and Cat Noir's staffs and is surprisingly skilled. When Copycat is distracted, gloating about himself, Ladybug uses her yo-yo to steal one of the staffs, returning it to Cat Noir. She also uses her yo-yo to catch the arm of one of the Cats, who protests that he is the real Cat Noir. The other Cat immediately insists that the first one is lying. Irritated with both of them, Ladybug demands to see how many toe beans they have left on their rings. The Cat she caught with her yo-yo turns out to be the real one, as he is down to one dot, while Copycat hisses in frustration, hiding his ring and making three dots disappear at once. Ladybug releases Cat Noir, and the two Cats resume fighting.
Using her lucky vision, Ladybug spots one of the staffs (lost earlier during the fight), a support beam on the ceiling, her yo-yo, and the spoon from her Lucky Charm. She makes a fishing rod with the staff, the yo-yo, and some duct tape that she tears off, bending the spoon into a hook shape. She catches Copycat by the belt with her fishing rod and swings over the beam, suspending him from the ceiling. She then takes the photo from his pocket and tears it. The Akuma flies out. Ladybug catches it, purifies it, and summons the Miraculous Ladybug to return everything back to normal; the Mona Lisa is returned to the Louvre and Copycat turns back into Théo.
Cat Noir is relieved that Ladybug could tell him apart from the fake. She retorts that it wasn't so difficult once she knew who was really in love with her, referring to Théo.
Down to his last dot, Cat Noir takes his leave, remarking that Ladybug has broken his heart as well as Théo's, but she doesn't hear him. Ladybug apologizes to Théo for not showing up to the statue reveal earlier that day and autographs his photo, complimenting him on his work. Still believing that Ladybug and Cat Noir are in a relationship, Théo says he is okay and promises not to tell anyone, to which Ladybug responds with confusion.
Cat Noir returns to the school as Adrien but eventually goes home, unable to find his phone. With Alya's help, Marinette manages to get past the pattern lock and delete the voicemail. She sneaks the phone back into Adrien's bag at school the next day.
Adrien is bewildered to find his phone in his bag, as he has checked there a thousand times. Nino says he needs to clear his head and suggests that they go see a movie that night. Alya asks Nino if it's okay for her and Marinette to tag along, and Nino agrees that that would be cool. Adrien turns around and smiles up at Marinette. Marinette jumps for joy, ending the episode.
Characters
Major characters
Marinette Dupain-Cheng/Ladybug
Adrien Agreste/Cat Noir
Hawk Moth (with Gabriel Agreste's pictured)
Tikki
Plagg
Akuma
Théo Barbot/Copycat
Minor characters
André Bourgeois
Alya Césaire
Adrien's bodyguard
Nadja Chamack
Roger Raincomprix
Nino Lahiffe
Lê Chiến Kim (background)
Caline Bustier (background)
Chloé Bourgeois (background)
Sabrina Raincomprix (background)
Mylène Haprèle (background)
Ivan Bruel (background)
Nathaniel Kurtzberg (background)
Juleka Couffaine (background)
Rose Lavillant (background)
Max Kanté (background)
Tom Dupain (pictured)
Policemen
Civilians