He’s the dumbest dog west of the Pecos River, and even when he’s not sharing one of Lucky Luke’s adventures, he’s still a walking disaster! The first solo adventure of the only dog stupider than his own shadow. 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!

After inadvertently thwarting a convict’s escape attempt, Rin Tin Can flees the penitentiary and ends up with two sheep herders who are being targeted by wool thieves. The robbers, Giuseppe and Aldo, are actually looking for a specific sheep skin tattooed with a treasure map, in order to post their father’s bail. Unwittingly – as usual – Rin Tin Can becomes first the accomplice of the two not-too-bright brothers, then their ‘godfather’ …