Grove places her characters in a small town in northwestern Missouri, not far from the Kansas line. Carly's life centers on the farm fields and the thick trees of Kosh Woods. Not far away is Dustin's starkly different environment—a dark narrow cave, Flat River, and his home with the muddy yard on the swampy river bottom near the county landfill.

Dustin Groat's ancestors rode with Quantrill's Raiders, a guerrilla band who fought for the Confederacy during the Civil War. Among the riders who joined Quantrill were outlaws Cole Younger and Frank and Jesse James. Years before Dustin's time, Cole Younger had dug an escape tunnel from a shed on the Groat compound to a cave, which exited deep in Kosh Woods.

Dustin uses the tiny tunnel as a place to hide from his violent family. Grove uses these historical facts to link the desperate men in...