A coffin is dug up by builders in the grounds of an historic convent - inside is the body of a young nun.  In a city as old as London  the discovery is hardly surprising. But when scratch marks are found on the inside of the coffin lid  Detective Jane Tennison believes she has unearthed a mystery far darker than any she's investigated before.  However  not everyone agrees. Tennison's superiors dismiss it as an historic cold case  and the Church seems desperate to conceal the facts from the investigation. It's clear that someone is hiding the truth  and perhaps even the killer. Tennison must pray she can find both - before they are buried forever . . .  In Unholy Murder  Tennison must lift the lid on the most chilling murder case of her career to date.