Lucky Luke gets caught between settlers and the ranchers in a land feud that threatens to tear Daisy Town apart. When Luke discovers that the mysterious Mr. Joseph is at the feuds center, offering to sell a "secret weapon" of defense to both sides, Luke investigates. Luke discovers that Mr. Joseph is none other than the dreaded outlaw Joe Dalton himself, with a stockpile of gunpowder kegs ready to fuel the feud. Before he can expose the plot, Luke and a settler girl named Louisa are trapped in a mine with gunpowder. Will Luke save himself and his beautiful partner? Remember he's called LUCKY LUKE!