Scotland Yard detective Ian Rutledge is assigned one of the most baffling investigations of his career - a cold murder case with an unidentified victim and a cold trail with few clues to follow.

Chief Inspector Brian Leslie, a respected colleague of Ian Rutledge’s, is sent to Avebury, a village set inside a great prehistoric stone circle not far from Stonehenge.

A young woman has been murdered next to a mysterious, hooded, figure-like stone, but no one recognizes her - or admits to it. And how did she get there? Despite a thorough investigation, it appears that her killer has simply vanished.

Rutledge, returning from the conclusion of a case involving another apparently unknown woman, is asked to take a second look at Leslie’s inquiry, to see if he can identify this victim. But Rutledge is convinced Chief Superintendent Jameson only hopes to tarnish his earlier success once he also fails.

Where to begin? He, too, finds very little to go on in Avebury, slowly widening his search beyond the village - only to discover that unlikely - possibly even unreliable - clues are pointing him toward an impossible solution, one that will draw the wrath of the Yard down on him, and very likely see him dismissed if he pursues it. But what about the victim - what does he owe this tragic woman? Where must his loyalty lie?