She excels as an assassin. Will she fail at love?

Vampires are real, existing alongside regular humans as a secret subspecies. The malevolent of their kind exploit their powers and immortality at the expense of their human counterparts. The Organization, a league of benevolent vampires headed up by the anonymous Mr. X, works covertly to keep this threat in check. Amber Ridley is the company's top agent, unique to the team as the only human working alongside her vampire allies. She is an 'Impervious', a rare human with powers that can be used against the malevolent.

When Amber's latest mission takes her back to the UK to work with her close companion Valentino, she meets his old colleague Hayden Knight. Hayden is infamous to Amber as the man who betrayed their organization and abandoned her friend Valentino in the past. She dislikes Hayden instantly, and his arrogant, cold demeanor does nothing to aid this.

Amber and Hayden are forced to work together on The Organization's most important mission to date, and they must put aside their differences to take down the menace that threatens the very existence of their group. Amber must put her trust in Hayden, but is she impervious to love?