Marinette is surprised to discover that a former schoolmate, Socqueline, is passing herself off as Ladybug. She tries to dissuade her from endangering herself this way, but Monarch comes after Socqueline, convinced that she is the real Ladybug. He entrusts an akumatized villain with the power of the Miraculous of Jubilation, which shows people their deepest desires. Will the real Ladybug and Cat Noir escape that dangerous power?