Death In Bordeaux, the first of Allan Massie's trilogy of detective novels set in Vichy France, ended with none of the triumphalism or closure one expects from the genre.

It was tantalisingly incomplete, like a sentence half uttered, or a thought only partially expressed. As the introspective, taciturn chief inspector Lannes faded from sight, anguished at being beholden for the release of his son, a prisoner of war, to men he deplores, the reader knew the occupation of his beloved city was going to make further and tougher demands on him.

Just as one feared, as Dark Summer In Bordeaux opens, life for Bordeaux's citizens is deteriorating fast. It is less than a year since the Germans marched into the city, but nobody is under any illusions about what the new regime portends. As Lannes sets out to investigate the murder of a Communist professor of literature, simmering tensions come to the boil. The city's Jews begin to feel the net closing around them, as do its gays.

When Lannes comes under pressure to close the case without an arrest, lest it embarrass his superiors and their German masters, he quietly, and then openly, resists. Thus, although the links between the professor's murder and events in the first novel are laid bare, this story is less about solving a crime than about conscience, with Massie turning the workaday beauty of pared-down detective fiction into a moral enquiry.

Chief Inspector Lannes's home-life neatly encapsulates the conflicts faced by the occupied French. His elder son, returned from internment camp, wants to do his bit for the newly collaborative France. His younger son Alain's thoughts are turning to resistance.

Meanwhile, Lannes's daughter fancies she's in love with a German soldier, and his wife Marguerite typifies those whose only concern is for the safety of their loved ones, regardless of the wider political picture. When the gulf between her values and those of her husband becomes apparent, their faltering marriage grows even more precarious.

Massie's refusal to offer a simplistic or trite solution means that by the conclusion of this sequel, one still has no idea whether by the trilogy's end one will feel relief or sorrow, or both. The year between now and the final novel's publication will crawl.