Hearts In Darkness. Number 2 in series

Life has never been so insane for Private Investigator Nikki James: a teenager is missing; a madman is kidnapping the wealthy; she's got a vampire to contend with; and her partner and best friend, Jake, is in the hospital dying. And just when it seems like nothing else could possibly go wrong for her, Michael Kelly returns. The last thing Michael needs is a confrontation with Nikki - especially when his control over his bloodlust is still so tenuous.
But when a kidnapper steps up his agenda to murder, they are suddenly forced into a partnership. Soon Michael discovers the biggest danger may not be from his need to 'taste' Nikki, but from his desire to make her a permanent part of his life - a life that is sure to get her killed. Nikki is determined to make Michael see that life apart is worse than death. But before she can make him see the light, a spectre from Michael's past rises that could destroy any hope she has of a future with him.