A general amnesty puts the Daltons back on the streets, something Lucky Luke isnt happy about. And, to make it worse, they seem to have become model citizens. Its all an act, though, and it doesnt take long for the stupidest quartet in the West to be back behind bars. Luke is already riding off into the sunset… But hes not counting on a riled-up Apache tribe that attacks the penitentiary where the Daltons are locked up…