One Foot in the Grave is the second novel in the "Night Huntress" series by Jeaniene Frost. While I loved the first novel in the series called Halfway to the Grave, I actually chose to read One Foot in the Grave because it qualified for June's Monthly Keyword Challenge at Bookmark to Blog. "Grave" was actually one of June's keywords.
One Foot in the Grave picks up about four years later, and Cat Crawfield is now working as a Special Agent for the government to control the world's undead population. Having spent four years without Bones -- her vampire lover -- Cat spends most of her time working and avoiding the dating scene. After she meets the vampire who had turned Bones years earlier, Cat learns that there is a price on her head, which is not surprising given her reputation as the world's most bad-ass vampire slayer.