The main character, Joseph Tullen, wakes up in a dark room, tied up and afraid with no memory. When he learns of a deadly disease that has plagued the world during is escape from his captor, he is told that he needs to go south if he is going to survive. He meets many different people along his travels with his sister, who escaped the captor with him although even with their help, it is a struggle to stay alive. In a world where few people are alive, and those who are, are infected, him, his family and friends must find clever ways to survive.