In the context of the abolition of cultural boundaries, the United States welcomes the ambassador of European culture, the great Sarah Bernhardt. This is not the taste of the league of virtue that is threatening to him. Lucky Luke is then charged by the president of the USA, Rutherford B. Hayes, with the protection of the Diva. Then begins a sown tour across the United States where it will be discovered that intolerance can do a lot of damage.