In the future, society has fractured. Rachael works in a library on the surface, very close to the entrance of an underground city. They are dangerous places; at least, she has been told that they are dangerous for people like her… people who are a little… different from normal. Rachael met someone, someone from the city and he changed her life but not in a good way. Now, she is on the run, pursued by people who want to kill her but she doesn't know why.