The book centers around a racist colonel, Wesley McCulloch and his black pursuer, Troy Harmon. McCulloch and Harmon both originate from the modern era, the book opening with Harmon called in by a special military watchdog organization to investigate why McCulloch has been buying large quantities of gold.
The case worsens when it is discovered McCulloch also murders three people to cover his plans. The theft of an antique Sten gun and the plans for such also add to the mystery about what McCulloch is up to.
Before long, Harmon comes to the conclusion McCulloch has used a secret experimental time machine to try to change the outcome of the American Civil War, giving victory to the Confederacy through the introduction of the easily produced Sten gun (which had yet to be invented). Harmon determines he must follow McCulloch into the past to bring justice. During the ensuing chase, Harmon discovers first-hand the prejudices of the people at the time.