Inspector Samuel Moss specialises in so-called perfect murders - those which are carefully thought through, planned out to the last detail and in theory impossible to prove. He works on the principle that the perfect crime is a well-oiled mechanism which nevertheless always contains a flaw, namely the criminal himself who, at some point down the line, will make a mistake.
This story begins when the best-selling novelist Jade Grivier is found dead at home in her study. It would appear that she has committed suicide with a bullet to the head, but Moss has learnt to be wary of appearances. After inspecting the scene of the crime in his own distinctive way, he comes to the conclusion that it is murder, not suicide.
But even if he manages to identify the guilty party, he knows that the game will not be over - the real difficulty in this type of case lies not so much in unmasking the killer, but rather in working out exactly how he went about his crime in order to prove his guilt.
This investigation will provide Samuel Moss with yet another element to add to his theoretical edifice for understanding the perfect murder - a theoretical edifice which he shares in his very individual way with his students, for he is also a lecturer at the Institute of Criminology...