Lila plants the answers to a test in Marinette's backpack, pretends to have been shoved down a flight of stairs, and claims she stole a necklace from her in order to turn Marinette's friends against her. Principal Damocles falls for her lies and expels Marinette from school. Hawk Moth senses the shock and despair of everyone who trusted her and turns Nathalie back into Catalyst, so he can assume his Scarlet Moth form and akumatize the entire school. Marinette nearly surrenders the Ladybug Miraculous under Scarlet Moth's orders, but Catalyst succumbs to exhaustion caused by the Peacock Miraculous, distracting Scarlet Moth and cancelling the procedure. Alya sets out to prove Marinette's innocence as Marinette is forced to work with her father in the bakery, while Gabriel forbids Nathalie from taking anymore action to protect her health. Nathalie goes behind Gabriel's back, forges a sentimonster in Ladybug's image, and attempts to trick Cat Noir, so she can get his Miraculous, but the real Ladybug shows up just in time. Together, she and Cat Noir resolve the false Ladybug on top of the Arc de Triomphe, but Hawk Moth intervenes and escapes with Mayura before they can unmask her. Afterwards, Adrien threatens Lila into proving Marinette's innocence, and Marinette is allowed to go back to school. But Lila still holds out on having revenge on Marinette in the future.