Set in a small town in the mountains of North Georgia, Though I Walk tells the story of twenty-one-year-old Anna Renfro, who discovers that her twin sister, Sam, has gone missing. Anna had escaped Marble Hill-colloquially named "Meth Hill"-and is away at college when she learns of her sister's disappearance. Anna drops everything and immediately returns home to find her family and the police investigation in disarray. Her mother, Jenny, copes by getting drunk and using dope, while her meth-cooking and dealing Uncle Brokeback uses violence and intimidation to look for Sam on his own. At first, everyone suspects that Sam has simply run away, but Anna's twin intuition knows better. While investigating the many clues regarding Sam's whereabouts, Anna comes into contact with a host of characters who both help and hinder her search.When the Georgia Bureau of Investigation and Sheriff's Department discover devastating proof that something horrible happened to her sister, Anna must face the chilling truth that there is much about her twin sister that she doesn't know. As the novel progresses, Anna finds that nothing is what it seems in her small, bucolic hometown: beneath the surface, Marble Hill is full of dark secrets where everyone is a suspect.

Anna ultimately learns that she cannot trust anyone-not even herself.