A constellation of two cops or detectives, an older one and a younger one. Inevitably, the older one becomes some kind of father figure to the other. In addition to that, they are often presented as very different from each other, which may or may not result in conflict between them. Maybe the older one is experienced while the younger one is new to the job. Maybe the younger one is emotional and short-tempered while the older one is more like The Stoic. Maybe the younger one is idealistic while the older one tends more towards cynicism. Maybe it's a case of Red Oni, Blue Oni. Maybe the older one is a rationalist while the younger one tends towards more intuitive methods of investigation - or maybe the other way round. If they appear in a crime or mystery setting (and they are very unlikel