The cowboy who draws a gun faster than his shadow is back! Lucky Luke, the famous wandering cowboy fights crime and injustice, most often in the form of the bumbling Dalton brothers. He rides Jolly Jumper, "the smartest horse in the world" and is often accompanied by Rantanplan, "the stupidest dog in the universe".

Lucky Luke, with his horse Double Six, travels the Old West to right wrongs and bring evildoers (usually his traditional enemies the Dalton Brothers) to justice. "The man who shoots faster than his shadow."

Given superstrength and durability by a sabotaged experiment, a wrongly accused man escapes prison to become a superhero for hire.

The story opens in a Western saloon, where a young musician with a banjo begins to tell a tale of Lucky Luke and his sworn enemies the Dalton brothers: Joe, William, Jack and Averell. Luke has, once again, as he has done many times before, thrown the four outlaws into jail. The prison is also the abode of a guard dog named Rin Tin Can (Rantanplan in the original French language version).