Cui bono? Cherchez la femme! These ancient maxims offer counsel to the investigator of an unsolved murder or some inexplicable pattern of behaviour. They advise the pursuit of what has come more recently to be known as a form of lateral thinking. The puzzle may not best be solved by an intensification of the examination of the immediate data. The primary clue may lie out of sight somewhere further back. Financial advantage or sexual attraction, which does not show up as a feature of the immediate situation, may be the hidden motive of the traditionally male agent's actions. When that is recognized, the otherwise inexplicable phenomena may become intelligible.