Alya shows Marinette a video she recorded of Ladybug talking to her, but Marinette accidentally deletes it. Before Alya finds out, Marinette steals her phone and frantically tries to re-create the footage. Meanwhile, Mylène's father, Fred Haprèle, has just picked up his fixed hat from Marinette, and is getting his first premier gesture performance called The Mime's Extraordinary Adventures at the Eiffel Tower. However, his partner, Chris, deliberately makes him late at catching the troupe bus, and convinces their manager Sarah to let Chris take the lead role instead. Disheartened, Fred becomes akumatized by Hawk Moth and turns into "The Mime", a supervillain who can pantomime anything to make it reality, and attempts to seek revenge.

Collège Françoise-Dupont is sending two students to represent them at a video game tournament, where they will compete with other schools in a fighting game known as Ultimate Mega Strike III. After Marinette notices Adrien is one of the potential candidates, she participates in the selections in order to be able to team up with Adrien. She manages to defeat another candidate, her classmate, Max, who has been training for a whole year and was looking forward to participating. Upset about all his gaming training gone to waste, Max is persuaded by Hawk Moth and turns into "Gamer", a dark player who uses a pyramid-shaped mecha-like ship, from the Ultimate Mega Strike III game that zaps people and objects, turning them into green "experience point" balls, which upgrades his ship. Ladybug and Cat Noir has to fight him in a similar videogame fashion with the battle between robots.