The Repairman Jack novels are a series spun off from the Nightworld novels (AKA the Adversary Cycle) by F. Paul Wilson. From The Other Wiki: 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.: blackmail). He is careful about whom 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 sci-fi & supernatural elements as the novels continue. The second novel, Legacies, is the only one that is completely free of any overtly supernatural elements.