A woman has been murdered at the foot of a megalith shaped like a great shrouded figure. Chief Inspector Brian Leslie, one of the Yard’s best men, is sent to investigate the site in Avebury, a village set inside a prehistoric stone circle not far from Stonehenge. In spite of his efforts, Leslie is not able to identify her, much less discover how she got to Avebury—or why she died there. Her killer has simply left no trace.

Several weeks later, when Ian Rutledge has returned from successfully concluding a similar case with an unidentified victim, he is asked to take a second look at Leslie’s inquiry. But Rutledge suspects Chief Superintendent Markham simply wants him to fail.

Leslie was right—Avebury refuses to yield its secrets. But Rutledge slowly widens his search, until he discovers an unexplained clue that seems to point toward an impossible solution. If he pursues it and he is wrong, he will draw the wrath of the Yard down on his head. But even if he is right, he can’t be certain what he can prove, and that will play right into Markham’s game. The easy answer is to let the first verdict stand: Person or persons unknown. But what about the victim? What does Rutledge owe this tragic young woman? Where must his loyalty lie?