Retired FBI agent Brigid Quinn knows how difficult it can be to overcome one's past. But she is nothing if not a fighter. Even when the return of a serial killer from her past threatened to derail her new marriage, she managed to hold on to the life she's been trying to build in Tucson with her husband, Carlo.

At first, the new challenges in her life seem pretty mundane compared to a serial killer. After her sister-in-law dies, Brigid's nineteen-year-old niece Gemma Kate comes to live with her and Carlo, to establish Arizona residency before starting college. Brigid doesn't exactly love the idea, especially since there's always been something unsettling about Gemma Kate, but family is family. Meanwhile, Brigid agrees to help a local couple by investigating the death of their son—until dangerous things start to happen. As the menace comes closer and closer to home, Brigid starts to wonder if she can trust anyone.

After spending her career hunting sexual predators, Brigid has seen her share of evil. Nevertheless, the worst threats are not always easy to spot, even when they are right in front of you—partly because few people manage to be pure evil. But Brigid knows it's what you don't see, what you never expected, that can be the most treacherous...