A prequel of the series. Hawk Moth captures a kwami named Nooroo and forces his allegiance. The butterfly brooch allows him to give people what they desire bound to obey his will. He plans on using this task to create villains to lure the heroes out to fight them, so he can steal their Miraculouses and gain absolute power. Master Fu, a Chinese healer, is notified of Hawk Moth's capture of Nooroo through Wayzz, his own kwami. However, he is too old to fight anymore, so he pretends to be senile, walking Paris to find suitable hosts for the Black Cat and Ladybug Miraculouses. It's Marinette's first day of school, and also Adrien tries to attend since his father wouldn't permit him. Marinette is unhappy that Chloé stolen her seat. As school is dismissed, Ivan and Kim have a dispute, after Kim sends Ivan an offensive message on paper. Feeling hopeless, Ivan becomes Hawk Moth's first ever victim, turning into Stoneheart, a giant rock monster who grows in size after taking hits. Fu is helped by Marinette and Adrien, and quickly deploys both the Miraculouses to them. Finding a small box in their rooms, and after opening them, they are greeted by Tikki and Plagg. Both kwamis give their hosts a quick explanation; soon Marinette and Adrien transform into Ladybug and Cat Noir. Despite their lack of experience and poor fighting skills, they manage to defeat Stoneheart at the stadium and free the akuma. However, Ladybug forgets to purify the akuma; it flies off, multiplying itself and infecting many people, turning them into immobilised Stonehearts. The episode ends as Marinette learns of her mistake, and thinking that she cannot do her job, removes her earrings and puts them away under her dressing table, causing Tikki to disappear.