All of the episodes open with Bathurst portraying Mark Taylor, a sitcom writer, apparently performing stand-up in a small comedy club. These performances are fantasy sequences, playing out in the character's mind and portraying his internal creative processes as comedic monologues; these monologues mainly employ material from the character's failing marriage and are intended to show that "he thinks in punchlines, in comedy". Episodes regularly cut back to these fantasy performances, which usually open with the signature line: "My wife left me ...". Moffat felt that audiences needed to know from the start that the relationship would not survive. However, it was unclear to some viewers that the fantasy sequences were set in the writer's mind; many journalists reported that the character Mark was a stand-up comic, not a sitcom writer.