Arriving at the town of Fort Smith with a prisoner, Lucky Luke is surprised to find a place in turmoil and a thoroughly annoyed sheriff. Belle Starr, a rich ranch owner, keeps posting bail for every bandit arrested in town, with the complicity of a corrupt judge, before recruiting them in her own gang and carrying out various attacks and robberies. Unfortunately, she is also such a pillar of the community that no one believes she could possibly be guilty...

In a fort on the Frontier, the 7th Cavalry keeps a vigilant watch over the Wild West. It is a time of peace with the local Natives, and all is well, thanks - at least in the colonel's mind - to the regiment's lucky mascot. But when that dog mysteriously vanishes and bad luck begins to plague the unit, it becomes necessary to find a replacement. The colonel picks Rin Tin Can for the job... and then the real trouble begins!

Everyone's heard of the Gunfight at O.K. Corral: the most famous shootout of the Old West, between the Earp brothers and Doc Holliday on the side of law and order, and the Clanton brothers and their gang. A legend told many times in books and films, in sometimes contradictory versions... Fortunately, here is the definitive version at last, restoring the unvarnished truth of what is another triumph of... Lucky Luke!