Emergence Day by Richard Palmer
A young girl manages to survive a nuclear plague that has destroyed much of the world was we know it. She emerges from a shelter underneath her house three months later to discover the world in ruins. The girl sets off on a journey to discover the fate of humanity and to learn more about her mysterious past.
Joined by a fellow survivor, the wanderer embarks on an epic quest across the scorched earth in search for answers. They cling on to one hope; to find civilization and seek salvation.