Lucky Luke is contacted by a rich individual with an unusual request: he wants to hire the Lonesome Cowboy to escort his stepdaughter Gisella on a trip across the Wild West. He wants her to see for himself the hard life of settlers and frontiersmen at least once before she settles into a comfortable married life. Luke arranges a few fake, safe incidents to entertain the young woman, but she's no shrinking violet, and tends to charge headlong into trouble ...