Hadrian just got his very first letter ever: Sidonie's inviting him to come over and dance for her birthday. But he doesn't know how to dance and would never dare—especially not with Sidonie! All his friends are excited to go, while his stomach is in knots with the sheer stress of it all! To help him, his father sends him for a dance lesson with a funny old lady, who asks him to make a wish. He wishes he will feel ready to go to Sidonie's birthday party! On the day of the party, Hadrian sets out, determined to face his destiny. When he arrives, he learns that the party has turned into a big treasure hunt!