Marinette's class must travel to New York to celebrate French-American Friendship Week. The whole class participates in it... except Adrien, because his father refuses to let him go. In anticipation of her departure, Ladybug asks Cat Noir to watch over Paris but does not specify the reasons for her absence. The latter takes the mission very seriously... but when Marinette, as a class delegate, convinces Gabriel to let his son go with his classmates, Adrien has a problem. Indeed, the schoolboy is also Cat Noir in secret, he cannot at the same time watch over Paris and be with his class in New York. How is he going to do that? If the two heroes are away, who will watch over Paris? There's one thing Ladybug and Cat Noir don't know: Hawk Moth is also getting ready to travel! The French-American Friendship Week interests him the most and it may well be that American superheroes need a little help! What can Hawk Moth have in mind when heading to New York?