Ten days to Christmas and Tracey Uphill, aged eight, hasn't come home from Sunday School. Her mother, a pretty young prostitute, is desperate. To help Frost investigate this case, he has been assigned a new sidekick, the Chief Constable's nephew. Frost proceeds with this investigation in typically unorthodox style, including consulting the local witch. He finds himself drawn into an unsolved crime from the past and risks, not only his career, but also his life.