Can you fight evil with evil...? DCC Bob Skinner faces his toughest investigation... Evil stalks the city of Edinburgh. This time the threat is bigger than the crooks, scam-artists or drug dealers who find their prey in the shadows of the streets. Some people are looking for a big-time hit. The body of a respectable businessman is found hanging from a tree; a veteran from a Belgian marching band is killed in a hit-and-run incident and another dies of an apparent heart attack. Excitement on the streets of Edinburgh is feverish as the city prepares for a huge rally to celebrate the return of Pope John the 25th to his hometown. The security has to be bulletproof. But there is a chink in the armour. Does Deputy Chief Constable Bob Skinner have the inner strength to find the answer to the biggest question of all?