Unfamiliar Magic is about a young witch named Desi, whose mom is also a witch and she refuses to teach Desi any spells or tell Desi anything about her father who has been absent Desi's whole life.  Desi has a cat named Devil which is a familiar. (Devil can travel to different worlds- the witch or the demon world) Desi's mom, Desi, and their cat have moved all over the world for an unknown reason to Desi. They have just moved to the suburbs when her mother leaves without any notice right after turning their cat Devil into a teenage girl.  After Desi's mother leaves unexplainably Desi is lost. She makes friends with the boy next door, Jarrett.  Devil, who is now called Cat, starts dating Jarrett's older brother, Bob.  Unfortunately Cat is just a person on the outside and still thinks like a cat, which causes problems for Desi.  When the foursome goes to the mall Desi meets a magician willing to teach Desi some magic.  Bad things happen after that include battling demons, learning magic, getting stuck in portals, and her mother and father fighting over what is best for Desi.