Fourmille Gratule now lives in New York, in the world of Ekho, a mirror world to Earth where modern technology doesn't exist.
As the head of the Gratule Artist Agency, inherited from her aunt Odelalie, she goes to Paris for a new contract with the Poulain Rouge cabaret. But she barely gets to the French capital before her body is taken over by the ghost of Prince Antone, Napoleon VII's son who died in a carriage accident. She will have to solve the mystery of his death to become her old self again...