It’s easy to think of a setting as a fixed element. London is London; it doesn’t move or change, right? While the location itself may be fixed, the city can look vastly different when certain variables are altered. The time of day, the weather, the season, even a change in narrator can make a setting look very different than it did just the day before. And no factor has more influence over the setting than mood.

Mood can be defined as the emotional atmosphere that a piece of writing creates—the feelings it evokes in the reader. It’s an important device because the mood of a scene prepares the reader for the events that will follow.

As an example, the audience’s very first view of the Bates Motel is unsettling. It stands alone on a scrubby hill, towering over the sparse trees. The exterior is dark and subdued. The windows are opaque—repelling the light and revealing nothing. This first glimpse elicits a feeling of unease from the audience; they instinctively know that something bad is going to happen here. This is the mood that Hitchcock created simply by introducing his movie’s setting.