Scotland Yard Detective Superintendent Duncan Kincaid and his partner Sergeant Gemma James return in another spellbinding novel of mysteries–one contemporary, one ancient–an investigation that will challenge them personally and professionally as no case ever has.

When Duncan Kincaid’s cousin Jack calls from Glastonbury to ask for his help on a rather unusual matter, Duncan welcomes the chance to spend a relaxing weekend outside of London with Gemma–but relaxation isn’t on the agenda. Glastonbury is revered as the site of an ancient abbey, the mythical burial place of King Arthur and Guinevere, and a source of strong druid power. Jack has no more than a passing interest in its history–until he comes across an extraordinary chronicle almost a thousand years old. The record reveals something terrible and bloody shattered the abbey’s peace long ago–knowledge that will spark violence that reaches into the present. Soon it is up to Duncan and Gemma to find the truth the local police cannot see. But no one envisions the peril that lies ahead–or that there is more at stake than they ever dreamed possible.

While his wife is consumed with her new case, Kincaid finds himself plagued by disturbing questions about several previous—and seemingly unrelated—cases involving members of the force. If his suspicions are correct and the crimes are linked, are his family and friends in mortal danger as well? Kincaid’s hunch turns to certainty when a Metropolitan Police officer close to him is brutally attacked. There’s a traitor in the ranks, and now Kincaid wonders if he can trust anyone.

As Gemma begins to see a solution to her case, she realizes she holds a child’s fate in her hands. Can she do the right thing? And can Kincaid rely on his friends, both inside and outside the Scotland Yard force, to stand beside him as he faces the deadliest challenge of his career?