Grand Duke Leonid of Russia is in Washington to sign a commercial treaty on behalf of the Tsar. But this larger-than-life aristocrat has read too much Fennimore Cooper and wants to visit the West. The US government is forced to agree to his whim—but wisely chooses Lucky Luke to escort him to the cattle capital of the West: Abilene. A good thing, too, because the Russian Grand Duke encounters real American desperadoes on his visit!