It is the summer of 1929 in central Alabama. Dunnigan prospers due to nearby industry and a booming economy. As train travel reaches peak popularity, the roads become more frequented by automobiles, and Highway 31 brings all kinds of people to and through the growing city.

After tragedy strikes, Sara Wheeler and her little brother leave Tennessee to live with their aunt. It is a new start, but the past haunts her as she scrambles to adjust.

Noah and Thomas Maclane left home to escape their overbearing father. On their own, they need to make ends meet. They find work at a local garage, but when they begin to live separate lives, the nature of their relationship poses a dilemma.

Ransom Cahill is part of a wealthy socialite family. He has every opportunity to succeed but wrestles with the expectations of life in the upper crust. His attempt to break free from those constraints brings unexpected danger.

These lives intertwine in Dunnigan, and it sets each of them on a collision course with their fears and insecurities. They must choose between the lives they have and the lives they envision, with no guaranteed destination.