Lotta Legs loves April 1st, Daisy Town dreads it, because of her April Fool pranks. Luke is summoned to the tent of a visiting Russian Prince, and Lotta Legs comes along. The Prince appoints Luke as his bodyguard and takes great interest in Lotta. Trouble starts when the Prince and his fiancée (who is jealous of Lotta) fight. The Prince declares that he'll marry Lotta instead. The Princess declares that she will marry a 'commoner' too - Lucky Luke! When Luke declines the offer, the Prince challenges Luke to a duel for offending the Princess...