Repairman Jack is a character in a series of novels by F. Paul Wilson. Jack initially was just one protagonist in a string of related novels, but then gained his own series known as The Repairman Jack series.
This series of novels uses realistic, thriller-like situations to tell a story with a broad supernatural theme. It is technically a spin-off branch of the aforementioned larger, overarching supernatural horror series, The Adversary Cycle.
Repairman Jack is a self-titled "fix-it" man, but not in the common workshop sense. He is something of an underground mercenary, hired by everyday people to fix situations that cannot be dealt with through legal means (e.g. by blackmail). He is careful about who he agrees to do fix-its for, preferring innocent, desperate citizens being victimized with no one else to turn to. These fix-its usually begin simply, but grow into complex problems that begin to involve more and more science-fiction and supernatural elements as the novels continue. The second novel, Legacies, is the only one that is completely free of any overtly supernatural elements.
All of Jack's fix-its are immediately relevant problems in today's world, covering topics such as conspiracy groups, grassroots movements, designer drugs, public shootings, terrorists, legal dealings and scientific and biological experiments. Jack relies on his brain, wits, experience and real-life weapons and techniques to do battle, and though he makes increasing use of supernatural sources of information (a spiritual medium), he has so far not used supernatural weapons or abilities in battle.
Jack hides his identity from the government and does his best to not leave behind traces of his identity when out and about. He advertises his services strictly by word of mouth and via an anonymous website.
Jack has two older siblings, and over the course of the novels a complex family history is revealed, along with a larger agenda that involves every member of his family.
He has a girlfriend with a young daughter, to whom he gives undying loyalty. Jack's best friend is an arms dealer and information specialist, and his other good friend runs a bar that Jack often uses as a checkpoint to meet with potential customers.
Jack is a man who carefully keeps himself outside of what he terms 'officialdom', refusing to enter the workforce (and claims to have no U.S. Social Security number). Because of this and the fact that he has earned many enemies over the years, his physical appearance embodies the word 'average': he is of average height, average build, with brown hair and eyes. He is physically fit but not obviously so; a confident fighter and skilled with guns.