This knowledge has granted him competent use of white magic, which he has used on occasion to overcome enemies or obstacles, but it is primarily his courage, wit and essential goodness that always enable him to triumph over supernatural evils (although the silver strings of his guitar and his possession of a copy of The Long Lost Friend are also powerful tools in fighting evil magic), while basic Army training allows him to physically deal with human foes.
On one occasion, he is "employed" by the State Department to investigate on their behalf a possible instance of Satanism (see the novel The Lost and Lurking for full details).
In the short story "Nine Yards of Other Cloth", John rescues a girl named Evadare from the unwanted attentions of the evil Shull Cobart: "Small-made, yet you saw she was grown and you saw she was proud ...
After Shull Cobart is destroyed, Evadare asks to join John on his travels, but he refuses to make her a wanderer like himself; when he can't dissuade her, he flees from her but she follows him.
In the following story "Trill Coster's Burden", after Evadare shows her faith and courage by taking a dead wicked woman's sins upon herself according to mountain custom (called "sin-eating": "Somebody dies after a bad life, and a friend or paid person agrees the sins will be his, not the dead one's") and watching out the night, she and John are married by Preacher Frank Ricks.
Wellman's friend, the author Karl Edward Wagner, wrote: "These stories are chilling and enchanting, magical and down-to-earth, full of wonder and humanity.
There is also a group of mini-stories or vignettes, consisting of about half a page, that were originally used as transitions from one major story to another in the collection Who Fears the Devil.