On the Edge of Darkness — Kerry Brown

Civilization on Earth was shattered by nuclear wars and an economic crisis late in the 21st century, and now, sixty years later, many areas have reverted to barbarism. Lena Reyes was a scavenger living in the industrial ruins of California, but she proved her worth to the corporations that rule the world and she returned to the enclave near San Francisco.Lena is sent out into the Wild once more, and she finds enemies that no one expects, or could even dream of in their nightmares. Lena must find ways to counter them, and fight her way out of the trap she and her companions have found.