Ananka Fishbein is a normal average girl, until she meets Kiki Strike and the rest of the Irregulars. Then her life changes dramatically. She sets out on a journey to map a city beneath New York, discovered by her mysterious friend Kiki. Only she and her friends know about this and they intend to keep it that way. Obviously this city once thrived, but now its only inhabitants are rats. Well, at least, they think that's right.