The power of a promise made and a promise kept is realized when Jeremiah Thompsett comes of age and accepts the responsibility of fulfilling his mentor's long-held dream. Raised by an escaped slave in the midst of the Arapaho nation in the Wind River mountains, he now must track down the slave catchers that killed his adopted father and stole their cache. The Vengeance Quest takes him and his companions through the mountains and across the nation to fulfill the promise of freeing the family of slaves held dear to his mentor and adopted father.

Accompanied by Broken Shield and Laughing Waters, his Arapaho friend and his sister, the trek through the mountains and to Fort Union is fraught with hazard and ambush. It is here he is joined by Scratch, the crusty mountain man who joins him on his journey downriver and across country to find Ezekiel's family and to seek to free them.