The complete collection DVD box set states "series 3 and 4 were contracted separately as individual series, however they were broadcast concurrently over a continuous period of 13 weeks in 1987." - so this episode is billed as Series 4, episode 1 on DVD. Nellie's hair is a totally different colour than in the previous episode which hints at episodes 8-13 being filmed at a separate time to the first 7 episodes.