"One Grave at a Time" by Jeaniene Frost

This sixth book in the Night Huntress series finds vampire Cat Crawfield, and her Master vampire husband, Bones, doing battle against a 500-year-old witch hunter who lives as a ghost 364 days of the year but becomes corporeal every Halloween to torture and burn alive three innocent women.  Ghosts play an integral part of this story as does Cat's cat, Helsing (as in the vampire hunter from Bram Stoker's Dracula), who is able to sense ghosts before the vampires can.

This story was especially action-packed with Cat testing out her new flying abilities and their best friends, vampire Spade and his half-demon/half-human wife, Denise, also trying to prevent Heinrich Kramer from his annual slaughter.  Interestingly, the witch hunter character was based on real witch hunter Heinrich Kramer, who wrote the Malleus Maleficarum back in 1486 to teach magistrates how to find and prosecute witches.  384 pages.