After losing the municipal election against Mr. Burgeois, D'Argencourt gets akumatized and turns into Darkblade! Using his sword he transforms people into knights and builds an army to turn the Mayor out. His forces storm City Hall where a class rep election battle between Marinette and Mr. Burgeois' daughter, Chloe, is brewing. It's up to Ladybug and Cat Noir to protect City Hall and all the students gathered inside!
