The Ghost Road is a story of war and struggle, both internally and externally. Set against the backdrop of World War I, readers follow the lives of Billy Prior and Dr. Charles Rivers. While Billy may be the first character introduced, it is Dr. Rivers who is truly the protagonist.

Billy Prior meets Dr. Rivers when he is a mental patient at Craiglockhart War Hospital, following his third tour of duty in the Royal Army. Their friendship continues after he's discharged through ongoing outpatient treatment. This treatment is more for Billy to salve his emotional wounds rather than any specific mental problem he's experiencing.

It's unclear why Billy wants to return to the Front for a fourth time, other than the fact that he doesn't know what else to do with his life. Fighting is all he knows. His inner struggle comes from his inability to determine who he is as a man. He continually cheats on his fiancée with both men and women. It is his fourth trip to war that causes his ultimate demise, as he is finally killed in battle.

Dr. Rivers' struggles daily with his own demons. His most significant problem is a perceived lack of effectiveness. Readers learn who he is through flashbacks of his mission trip to Eddystone, a Melanesian island. There, he compiles research on the villagers and plans to write a significant treatise, but his own ghost haunts him: the treatise is never completed or published.

The title of the book speaks to the ghosts, both seen and unseen, in all of us.