Toronto private investigator Vicki Nelson returns for her fourth adventure in Blood Pact.

After facing down a demon and a megalomaniac mummy and rescuing a family of werewolves, Vicki Nelson could claim she's seen it all, particularly when she can count a vampire as a close friend and lover. But none of her experiences can possibly prepare her for her mother's sudden death.

Wracked with grief and guilt, Vicki leaves immediately for Kingston. Vampire Henry Fitzroy and his rival for Vicki's affections, Detective Sergeant Michael Celluci, are not far behind, joining in an uneasy alliance for Vicki's sake.

It's hard to imagine things getting worse, but they do. At the funeral, Vicki discovers that her mother's body is missing from the funeral home, and she turns all of her energies to tracking it down. It isn't long before she is drawn into a web of murder and madness as she uncovers hideous scientific experiments at Queens University, where her mother worked and, in fact, died. Unlike her earlier cases, this time it's personal.

Vicki's determination to find her mother's body and the people who took it become all-consuming, forging a tighter bond of necessity between Henry and Celluci, faced with the difficult task of saving Vicki from her own drive. Inevitably, Vicki comes face to face with something even she can't handle, and it is up to Celluci and Henry to make an excruciating decision for her sake.

New levels of Vicki's character emerge as the bond between mother and daughter are explored. While Vicki has always been slightly flippant about and impatient with her mother's persistent meddling in her life, she has also felt a nearly lifelong responsibility for her mother. Helpless in the face of death -- and worse -- she has to confront a complicated tangle of emotions which also leave her vulnerable. Celluci and Henry also experience growth in their characters when they put their personal agendas aside for Vicki.

The villains in this case are human, which perhaps makes them the most horrifying creatures Vicki has ever faced. Grad student Donald Li is likable in spite of his role in the "research," but at times both the single-minded student Catherine and the administratively gifted Dr. Burke go a little over the top in their respective "mad scientist" roles. The pace of the plot makes up for any flaws in characterization, however, and Huff keeps things moving in toward a conclusion that anyone who has read the series thus far realizes is inevitable, if only in retrospect.