In his fifth case, Hunkeler is probing deep into Switzerland’s past. It’s the end of October and the city of Basel is as grey and wet as December. With his girlfriend Hedwig away in Paris for three months, Inspector Peter Hunkeler is back in his smoke-filled favourite pub nursing a few after work beers. It’s already the early hours of the morning when he sees old Hardy on his way home. Hunkeler sits down next to him and smokes a cigarette. But Hardy, usually so eager to chat, stays uncharacteristically silent. His throat is just a gaping wound. The media and city police are in agreement: a band of Albanian smugglers are behind the murder. But that’s too easy for Hunkeler, who decides to follow a hot lead using his own methods – and is promptly suspended. He clears out his office and puts his faith in his unmistakeable psychological intuition. It leads him to Basel’s red light district and to the dark, unknown depths of Swiss history.

It is high summer in Basel. After his early morning swim in the Rhine, Inspector Hunkeler witnesses a man jumping into the river from the Johanniter Bridge. At first glance it seems to be suicide. But Hunkeler has his doubts and soon he is on the trail of The Fluttering Man. It leads him to the very brink of legality and into the depths of his own past.

Peter Hunkeler, now a retired inspector of the Basel police force, hospitalized following surgery and shared the room with an old acquaintance: Stephan Fankhauser, a colourful character. Once a wild member of the 1968 student movement, over the course of the years he made his way through the institutions and became director of a bank. Now Fankhauser is seriously ill. One night, Hunkeler had just been given a sleeping pill, he noticed a nurse with a ruby ring on her hand administering an injection to the fellow patient. Strangely, Fankhauser is resisting it intently. And does not the night nurse usually wear a diamond ring? The next morning, when Hunkeler wakes up, Fankhauser is dead. Was it all just a dream? Hunkeler is not sure, but he resolves to get to the bottom of the matter.

On a hot summer Monday Inspector Hunkeler receives an urgent phone call from his family doctor's receptionist: Dr Christa Erni has been found murdered in her practice. Suspicious circumstances soon come to light concerning a group of drug addicts who were supplied with methadone by the liberal doctor. But Hunkeler's instinct for the darkest depths of the human soul leads him in other directions.

A young Turkish woman is found murdered, her face hideously cut. It seems obvious that her husband has murdered her out of jealousy, for just a few hours later he hangs himself in his cell. But Inspector Hunkeler does not believe the solution to the case is that simple and continues to investigate. What was the motive for this gruesome death in the St Johann quarter of Basel? Was it really jealousy and honour? Or could the Turkish mafia have something to do with it?