The Guild Wars: Magus

Liz Tanner never believed in magic until her grandmother asked her to come and work at her occult warehouse in downtown Indianapolis, Indiana. Things quickly become strange as she struggles to learn magic. while learning from a book called the Carlovasti, a group called Priori attacks. Now, instead of customers, she needs to be able to fight of evil mages and navigate around the magical government who is as interested in her little book of magic as the Priori is. Not to mention the Guilds that all want her and her power to themselves.