It's been four years and Cat is sure she's moved on: there's a new man in her life and her vampire-slaying is now government sanctioned. But, as she stand at the altar at her friend's wedding, Cat is stunned to make eye contact with one of the groomsmen - none other than Bones. Before either has a chance to adjust, it becomes clear that a hit has been taken out on Cat. The volatile pair must team up again as they track down the mole inside Cat's organization, prevent her father from killing everyone, and try to forge a lasting relationship in the dangerous world they live in.