What was that?

It's the party after Marinette's Coronation, and something is wrong. When school is done in Paris it means Marinette will have to go to China for becoming Queen. Will Marinette be able to find out what's wrong before something terrible happens? Or will she be able to face her fear of becoming Queen, and having Adrien become her husband? Will all of Paris find out the identities of Ladybug and Cat Noir?