Sometimes fires go out is a one-off sketch in Series 2, Episode 1. It begins with a clip of two people eating dinner. They decide to watch television, but one of then leaves a cigarette still lit in the ashtray. As they watch "Pride and Prejudice (which is originally believed to be "London's Burning") the cigarette ignites a curtain which blazes. Just before they get up however, the fire goes out. It then cuts to Webb interviewing David Mitchell about this, which is a clip from his film "Sometimes fires go out".
It is said by Webb to be similar to "A Man who has a Cough and it's just a Cough and he's Fine", which a clip is shown of. A woman, called Kylie, repeatedly exits a train, as a man greets her, who has a cough. The cough gets worse, until one time Kylie leaves the train to find no-one there. She believes he has died of TB, but he walks up behind her, stating "No, it was just a cough."
The interview continues, as Mitchell states that films lack realism. A clip is shown from another of his films, "The Gathering of People", where a man thinks he is going to sneeze several times, before properly sneezing.
The interview continues further, and they start talking about an episode of "Casualty" he wrote. A small child walks towards a pan containing boiling eggs, but is picked up by her mother, who looks out the window and says "Aliens!"