The ancient walled city of Canterbury has held many secrets over the centuries but none more mysterious than the death of Professor de Gray.

Called in to evaluate the contents of his Tudor Manor House, Belinda and Hazel are confronted with a number of suspects who would benefit from the book the Professor was about to publish; a book he promised would re-write the history of St Thomas Becket who was murdered in the Cathedral in 1170.

Confirming the Professor was murdered proves to be a challenge and, gradually, as they get to know those associated with the Manor House, Belinda and Hazel discover another murder and an intricate web of secrets that leads them to life-threatening danger and finally to the killer, in this fourth book of the series.