Again, this scene might seem fairly innocuous, but since it was also revealed in the first chapter that Fanthorp’s law firm has an interest in Linnet (and that they sent him specifically because of a letter in which she mentioned seeing Pennington), it seems clear that Fanthorp’s intervention here is very purposeful. Pennington’s annoyance drives home the fact that he and Fanthorp have competing interests, though Linnet and Simon both seem unaware of this.