Wycliffe and the Dunes Mystery by W. J. Burley
Cochran Wilder disappeared 15 years ago while on a walking holiday in Cornwall. Recently released from a psychiatric hospital after being convicted of indecent assault, he had been a serious embarrassment to his father, a prominent MP. Now his body has been found buried in the dunes and it is clear that he was murdered. Detective Superintendent Wycliffe suspects the involvement of six people, now well-established figures in the community, who at the time had been spending an illicit weekend at a chalet in the area. All are disturbed by Wycliffe's interest and by a series of threatening anonymous communications. But when a second murder is committed, the investigation takes on a whole new urgency.