Magali plays in a music band. Guillaume drives a small tourist train. Both spin a perfect love, share modest dreams and their baby is about to be born. But unexpected news upsets his routine: a man appears and announces that he is Guillaume's estranged father and also reveals that Guillaume is his rightful heir to a kingdom on the outskirts of France and England. Guillaume and Magali begin to dream of a life as monarchs, surrounded by faithful subjects in their castle, enjoying their riches. But reality is often different than what you imagine.