According to the book's cover sleeve's inside front flap: "From a Buick 8 is a novel about our fascination with deadly things, about our insistence on answers when there are none, about terror and courage in the face of the unknowable."

After a drunk driver kills Curtis Wilcox, a well-liked member of Troop D, his son Ned begins to visit the barracks.

Sandy Dearborn, now Sergeant Commanding of Troop D, is the main narrator of the book, and tells the story to Ned, discussing various things that have happened with the car and his father's fascination with it.

The car will frequently give off what they dub "lightquakes", or large flashes of purple light over an extended period of time.

Two people have disappeared in the vicinity of the car — Wilcox's former partner Ennis Rafferty, as well as an escaped lowlife named Brian Lippy.