Lucky Luke by... Blutch: Untamed follows the journey of Lucky Luke as he arrives in a small town to deliver a young man to the sheriff's office after an attempted theft of Jolly Jumper.

A few miles down the road, isolated in the vast wilderness, Luke finds himself unexpectedly threatened by a little girl. This young girl, Rose, and her brother are left alone in their cabin following the mysterious disappearance of their parents.

Faced with this new challenge, Luke must not only investigate the puzzling disappearance but also manage the task of caring for two particularly wild and undisciplined children.