Monarch has akumatized Cat Noir. And he turned a few citizens into regular cats, in addition to his powers. Except that Ladybug hasn't managed to stop him yet, and no one knows where the akumatized version of Cat Noir is at the moment. So... not possible to undo the effects right away.

Nathalie comes home from work, a little satisfied by the turn of events. This is one of the first times that Gabriel's akuma has not been defeated. She opens the door to the apartment she shares with a roommate, a policewoman around her age. Except there's no one there.

Or rather... she spots something on the sofa. A cat. The golden fur and the pink muzzle. How did it get in? It's at this moment that she notices the police shoes in the hall as usual, and the cell phone on the floor next to the sofa. Oh shit.