Queen of the dark things
(Book)

"Six months have passed since the wizard Colby lost his best friend to an army of fairies from the Limestone Kingdom, a realm of mystery and darkness beyond our own. But in vanquishing these creatures and banning them from Austin, Colby sacrificed the anonymity that protected him. Now, word of his deeds has spread, and powerful enemies from the past--including one Colby considered a friend--have resurfaced to exact their revenge. As darkness gathers around the city, Colby sifts through his memories desperate to find answers that might save him. With time running out, and few of his old allies and enemies willing to help, he is forced to turn for aid to forces even darker than those he once battled" --,from publisher's web site.