The story begins in western Pennsylvania in 1979, when a mysterious figure parks a vintage Buick Roadmaster at a local gas station, then disappears forever. The police discover that the Buick isn't a car at all but rather a Buick-shaped enigma: self-healing; impregnable to dents, dirt, and scratches; composed of unidentifiable materials; and containing a completely nonfunctional engine. Confronted with a mystery of unprecedented proportions, the troopers of Barracks D claim the Buick for themselves and spend 20 years attempting to understand its nature, purpose, and provenance.