Rye Mallett, a fearless "freight dog" pilot, is asked to fly into a completely fogbound northern Georgia town and deliver a mysterious black box to a Dr. Lambert. As Rye's plane nears the isolated landing strip, more trouble than inclement weather awaits him. He is greeted first by a sabotage attempt on his plane that causes him to crash land, and then by Dr. Brynn O'Neal, who claims she was sent for the box in Dr. Lambert's stead. Despite Rye's "no-involvement" policy when it comes to other people's problems, he finds himself irresistibly drawn to the intrigue surrounding his cargo…and to the mysterious and alluring Brynn. Soon Rye and Brynn are in a treacherous 48-hour race to deliver the box before time runs out.