Cnut - Deadly Premise

The German conductor of the West Norge Philharmonic Orchestra, Klaus Steiner, drops dead while conducting. A sexual predator, who drugs his conquests, so that he can rape them, he has dozens of enemies - all of them potential killers: the members of the orchestra he has raped recently, and the women he has raped in the past, their husbands and boyfriends, German haters, and the local drug dealers.
Cnut believes that it is also possible that the murder was impersonal, and carried out in order to hurt the sole owner of the orchestra, Karl Brekke. With so many suspects, and no clear motive, Cnut decides to tackle the most obvious one - revenge, first, and he and his team begin to investigate the female members of the orchestra, uncovering a web of sexual deceit. He and Ilse, by sheer chance, had made a booking to attend a performance by the orchestra a couple of nights later, and are enjoying the music, when Cnut, himself an accomplished pianist, notices a couple of wrong notes played by the pianist, Kurt Vogelsang, and sees that he is unwell.
A few seconds later, Vogelsang drops dead, and the possible motives change again, but since both the victims are men, it seems logical to continue to investigate the women. Viv Blenke, who does the autopsies, is stymied. That the victims have been poisoned is obvious, and she knows from the low protein levels in the corpses that a plant-based toxin similar to ricin must be responsible, but whatever poison was used, she can not find it in the bodies.
Then, a woman is killed, but this time with a knife. Two women make confessions, which muddy the waters, and Cnut is nowhere near finding an answer, until he begins to go well outside the box, acting on a tiny clue. He uncovers a most intriguing plot, and the final ironic twist astonishes everyone, but most of all Cnut and the killers.