When ancient evil wears a Christian mask, who can you trust? Reverend Thaddeus Grimsby thought his days of violence were behind him. But when a prominent nobleman is murdered in an impossible locked room, marked with blasphemous symbols, Grimsby's investigation reveals a conspiracy eight centuries in the making. The Order of the Midnight Cross has infiltrated every level of English society-the Church, Parliament, even the nobility. Their goal: to establish a new form of rule that blends Christian authority with pagan power. As the winter solstice approaches, Grimsby, and his best friend Professor Percival Marlowe, must stop a ritual that could transform England forever. But in a world where friends and allies hide deadly secrets, the greatest enemy may be closer than he imagines.