The leader of a chart-topping band is killed in front of his old friend, Elias Harmaa. Elias - or "Herr Grau" as he is also known in Germany - leads the team responsible for the security of the band on their world tour. Now he needs to find the killer. The task is puzzled with a bunch of diamonds found in his friend's possession, but as Elias proceeds with his investigations, he soon realizes that appearances may indeed be deceptive. After some breath-taking events in Munich and Bonn, Elia...