Waking the Witch - Armstrong, Kelley

Waking the Witch is book eleven in the Women of the Otherworld series.  Readers have watched Savannah grow up and come into her powers in this series.  This is the first novel where 21 year old Savannah is the main character and mostly working on her own.  She's dealing with a killer who's hard to pin down and keeps on killing while she tries.  The pace is fast and there's plenty of action.  Very highly recommended.