 The series initially focused around the character of half-vampire Catherine "Cat" Crawfield and her full-vampire lover Bones, but eventually shifted focus to other characters such as Vlad Tepesh, a character that Frost had initially not planned to include.The original "Night Huntress" series was initially planned to span seven novels, with Frost later extending the length to nine books.However, while writing the seventh novel, Frost decided that it would be the final installment in the main series.