Fourmille Gratule is now based in New York, in the world of Ekhö, a mirror world of the Earth where modern technologies do not exist. At the head of the artistic agency Gratule, inherited from her aunt Odelalia, she goes to Paris, accompanied by Yuri and Grace, for a juicy contract with the Poulain Rouge. But barely arrived in the French capital, she is inhabited by the ghost of Prince Antone, son of Napoleon VII, who died in an accident of fiacre. She will have to solve the mystery of her death to become herself again...