Grace Daniels is a career cop, a dedicated, single-minded DI in the murder squad. Unimpeded by any personal relationships, she commands the respect and loyalty of her team and seems destined to break through the glass ceiling of the force. Yet her life is shadowed by the recent death of her mother, her estrangement from her father, and her failure to solve what appears to be a ritual double murder in the parish church of the sleepy village where she grew up. Meanwhile, a prominent businessman is found with his brains spattered over the furnishings of his luxury apartment, and Grace is assigned to the high-profile case as Senior Investigating Officer. But there's a catch: she knows the victim personally, and though she ought to disclose the connection to her boss, she remains silent. As the investigation is underway, it is soon revealed that there is a mole in Grace's team, someone working to undermine and discredit her at every opportunity. As the truth emerges it becomes clear that Grace is far more vulnerable than she appears and is mired in the kind of trouble that could deprive her of much more than just her job.