Within both society and the human mind, order and stability are constantly threatened and interpreted by the darker elements of the irrational. It is to our sense of this threat, to our apprehension of disorder, both conscious and unconscious, that the detective story appeals. The suspense it creates and uses though, can be, paradoxically, not merely a passive and alarming but also an active and pleasurable experience. Crime or murder may shock and disorientate, but the suspense arising from ferreting out clues, from tracking a subtly devised sequence of events to a satisfying conclusion, can be both enjoyable and stimulating. The basic structure of a detective story is, after all, rational, and some suspense is inevitably derived from speculation on when and how order will be re-created from apparent confusion.