Detroit Police Department Detective Sergeant Jericho Jackson, known locally as "Action Jackson", was a celebrated lieutenant in the police force but demoted (nearly two years before) because of a case he headed involving the criminal son of successful businessman Peter Anthony Dellaplane. The fallout over the case also collapsed Jackson's marriage and put the law-school-educated, star athlete and hometown hero at odds with the public. Even after his demotion, Jackson's continued interest leads to conflicts with his commander, Captain Armbruster, but he begins investigating Dellaplane's professional exploits, eventually uncovering a string of murdered trade-union members connected to Dellaplane's company. He discovers Dellaplane is secretly maneuvering into a "behind-the-throne" seat of power, and has been using a group of assassins, "The Invisible Men", to murder uncooperative union officials.