The world ended quietly. Cities fell to ruin, highways emptied and the silence grew louder with each passing day. Dr. Clyde Viridis might be the only one who can stop it. Brilliant, haunted and running out of time, he carries the challenge of developing a cure. At his side is Kanin, a battle-scarred soldier with one mission, to keep the doctor alive. Every mile of desolate highway brings new threats and the gnawing question of whether the cure can be finished in time.