It's time for the queen's Grand Ball and everyone in the Kingdom of Klue is invited! Ava and Gabby wear their finest dresses and practice their best manners. Everything is going swimmingly--until the palace is invaded by frogs! How did they all get in? Where are they coming from? It seems even their pet frog, Erk, doesn't have a clue! Ava and Gabby must put on their thinking crowns to solve the case. Can they unravel the mystery before the guests arrive