One of the main differences between the thriller and the detective story proper is that the former demands an open, the latter a closed environment. The classic example of the second is the country-house murder. Peter Dickinson, in a series of highly intelligent novels, has taken this formula and stood it on its head by creating a succession of strange closed societies that are not simply neutral arenas for the conflict between murderer and detective but are fascinating in their own right. In them the crime and its detection are defined by the bizarre environment, and it is probably this which has forced his detective, Jimmy Pibble, most sympathetic of fictional policemen, into premature retirement; the normal procedures of investigation are unavailing in the outré worlds conceived by Mr Dickinson….

Peter Dickinson tends to look at things from the standpoint of an anthropologist: custom and ritual bulk larger...