Cécile, a 10-year-old, moves to the south of France with her mother, Louise. Integration with the other children of the village is not easy. When a passing circus sets up next door, Cécile discovers that Poly the star pony is being abused. She decides to protect him and organize his escape! Pursued by Brancalou, the disturbing director of the circus, and the mysterious Victor, Cécile and Poly embark on a run full of twists and turns, a true initiatory journey and an incredible story of friendship...