It's the last day of the Louds in Paris.
On their last day on Paris, the Louds are packing their things to return to Royal Woods to rebuild their house. But Leni is still unconscious. Lincoln tries to reanimate her using expensive cloth and jewels. But it doesn't work. According to Butterfly Effect, if Leni is hit on the head, it become smart, but as the hit was of a metallic beam rather than 5 pairs of boots, it means the change could be bigger.
Leni finally awakes of her dream in this arc, but instead of greeting all like always, proceeds to answer sarcastically saying something like "Who are this weirdos? Oh true, they're my family". The others look at her with strange eyes. Lori asks if she's okay. Leni answers (with sarcasm) that yes, she's very good mentally to visit North Korea in middle month of Kim.
During all the day, instead helping the others, Leni only thought in her own benefit. An example is taking all the weenies at the fridge to make hotdogs... for herself alone. The others think the hit, being stronger, must altered her brain to do all the opposite of the things she would do normally, in few words: act for her own benefit rather for the others', don't be too innocent to real life, and saying many things indirectly. Lincoln asks Lisa if there's a cure for that behavior. Lisa answers it could be something more than cerebral, that could be also of blood. When they checked the circulation, they noticed the blood ran to the other side.
It's time to fly, Leni is still being sarcastic, the others don't tolerate her anymore, and even menace with leave her in Paris. BUT, Leni only answers with a cold stare, leaving that place. As she only has €100 left, she decides to buy a ticket to Royal Woods for herself alone. The others left dissapointed with a low head. Once at the plane, the others remember the old Leni of 100 episodes ago. A Leni, even dumb, always cared the others before her. That had a hidden talent (the sculptures), and the change is hard, but at long you get to it. Now you will ask: Leni will remain that way for the rest of the series? Well, I don't know how to tell you buddy. Only read the season, and you'll know.