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, that is, until the palace is invaded by frogs! How did they all get in? Where are they coming from? Readers in grades 1-4 will help Ava and Gabby put on their thinking crowns to solve the case. Can they unravel the mystery before the guests arrive and the ball is ruined? Princesses Ava and Gabby Danger love martial arts and putting on their thinking crowns to solve mysteries in their castle, their classroom, and beyond in the Kingdom of Klue. Joined by their sidekick, Erk, a frog they will never kiss even if he might be a prince (ick!) the ninja princess detectives find the clues, follow their hunches, and save the day.