Ava and Gabby can't wait for Klue Kingdom's annual Taekwondo Tournament at the palace. To celebrate, Ava bakes their sensei her special chocolate chip cookies. But everything goes wrong when Sensei Suki gets sick! Was the cookie dough tainted? Or is someone trying to sabotage the tournament? Readers in grades 1-4 will help the girls put on their thinking crowns to solve this mystery! Can they clear Ava's name and cure Sensei Suki before the tournament is canceled? 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.