Magali, a tuba player in a brass band, and Guillaume, who drives a little tourist train, lead a peaceful life in the suburbs. Their love is still as strong as the day they first met, with their modest dreams and a long-hoped-for pregnancy. But things get complicated when Guillaume’s father, whom he doesn’t know, contacts him to announce that, by virtue of an agreement dating back to the Middle Ages, he is the heir to an authentic kingdom off the coasts of France and England. Guillaume and his wife are disbelieving at first. But the prospect of reigning over an idyllic island, with faithful subjects, a castle and a fortune... is very tempting! However, the reality is far from what the couple imagined. The island is nothing but a shabby rock, battered by the North winds and inhabited by only five rather eccentric people...While Magali is getting excited about her future status as queen, their new servants try to outdo each other with twisted plans to hide the truth from them, until Guillaume can no longer renounce his crown.