Detective Abigail Paxton is changing, both physically and psychologically. As she continues her metamorphosis, she isn't sure what to fear more; the thing she is turning into, or who she is becoming. After her final encounter with the vampiric creature, Piper, Abigail hasn't been the same. Her body is changing and she has developed a taste for...a different kind of nourishment. Now, she fears that the people she was once sworn to protect, might need protection from her.

But Abigail has help navigating her newly acquired lifestyle. Her younger sister, Dr. Marybeth (Bethy) Paxton, can see the changes happening within Abigail and as a pediatric doctor at Saint Ambrose General and protective sibling, she will stop at nothing to save her sister. But Bethy doesn't just want to save Abigail, but everyone around her, and will do whatever it takes not to lose anyone else under her care, no matter the costs.

Abigail and Bethy's choices will lead the Paxton sisters on a journey of terror and carnage as new threats emerge, all stemming from the blood of Abigail. Will Bethy be able to save those she loves most? Or has she damned everyone around her, including Abigail?