Richard Coyle quit the show at the end of the third series so a new character - Oliver - played by Richard Mylan was introduced. There was much resistance to this move as Coyle's character had been one of the most popular.
Unlike the first three series which were broadcast on BBC Two, this fourth and final season was transmitted on BBC Three.
The episode's title is a reference to each segment in the story, as they are all nine and a half minutes long.
During Steve's phone call with Jeff, it is implied that the latter connects the island Lesbos with the word "lesbian". In fact, that word actually originated from the island Lesbos.