While Lucky Luke bring the Daltons to jail trough the Mossback Indians tribal territory, their leader Joe accidentally saves the life of the clumsy son and unwilling heir of the chief when they both fall into a torrent. As reward, he is adopted as the old chief's second son, all Daltons get sanctuary as blood-brothers. Lucky soon also saves the bumbler, and is confident the crooks won't keep up Indian life, especially as the chief's gigantic daughter has the hots for Joe...
—KGF Vissers