Another strong feature of the series is the continual linking between the books. This may be in reference to background, previous cases and storylines, or through the characters Rebus encounters, for example, the notorious Edinburgh crime lord 'Big Ger' Cafferty. Rankin does this in such a way that reading them in order, prior knowledge of the Rebus 'history' is not required. Everything is explained in enough detail in order not to confuse new readers, but does not become repetitive for extensive readers of the series.