Upon its initial airing on BBC One, the series was presented in three hour-long episodes. In every other territory, it was re-edited into four 45 minute-long episodes. Thus the 1st episode of the four part version covers events of the 1st episode of the BBC version, the 2nd covers the rest of the 1st BBC with some of the 2nd, the 3rd the rest of the 2nd BBC with some of the 3rd and the 4th the rest of the 3rd BBC.
