A 30-year-old case is being reopened and Rebuss team from back then is suspected of foul play. With Malcolm Fox as the investigating officer are the past and present about to collide in a shocking and murderous fashion? And does Rebus have anything to hide? His colleagues back then called themselves The Saints, and swore a bond on something called the Shadow Bible. But times have changed and the crimes of the past may not stay hidden much longer. Who are the saints and who the sinners? And can the one ever become the other?