The Kate Daniels Series is a popular urban fantasy book series written by authors Ilona Andrews. It follows the story of Kate Daniels, a strong and resourceful mercenary living in a post-apocalyptic Atlanta where magic and technology fluctuate unpredictably. The series combines elements of magic, mythology, and adventure, featuring a rich cast of characters and a detailed world. Throughout the series, Kate navigates various challenges, including conflicts with supernatural beings and her complicated relationship with Curran, the powerful Beast Lord. The books explore themes of loyalty, identity, and the struggle between good and evil, making it a captivating read for fans of the genre.