Scene Anatomy: Throughline, Story and Beats
Scene work is important because it is what your actors will use to get through the movie. The strength of it helps your director figure out what the hell the movie is about, and gives fans stuff to quote (how many times have you seen somebody hold a mug and ask for a cover on that TPS Report with a smug grin?). It's also the subconscious difference between professionals and amateurs, between folks that get jobs and folks that want jobs they can't get.
Now, let's look at it from the three things that every scene must do: 1) Propel the character through the plot; 2) Solve the character's immediate dilemmas as they solve the plot; 3) Reveal the moment-to-moment actions of the character as he/she solves the dilemmas that make up the plot
Part one above is what is referred to as the "throughline". It's what the movie is really about: THE TERMINATOR is about a woman accepting her fate as the mother of the future savior of the world. The throughline is her transformation from timid, shy, lonely heart, to strong, brave lover and fighter. This level of the story is where themes come into play. Themes about faith, redemption, love, loss, betrayal. The things that make a movie watchable again and again.
Part two is the "story," the how of the transformation. We see her at home with her contrasting outgoing roomie, at her job as put upon waitress who can't get her orders right, as awkward third-wheel when she is stood up by her date, feeling sorry for herself at a local bar when she hears about the second killing and realizes that she might be next and all this entails as she embarks on her "hero's journey."
But scene work is composed of part three, above. It is those "beats" -- the ones talked about so much in screenwriting books and classes. They are the actions that a character undertakes during the course of the story. For example at the top of the scene at the bar after Sarah has been stood up by her date, she is drinking, then, in the b.g. she hears the TV anchor announce the second Sarah Connor killing, she asks the bartender not to change the station, then rushes to the phones to call the police when she realizes she might be in danger. The phones are out of order forcing her to leave the relative safety of the bar and head for the streets.
Broken down another way, Sarah's initial motivation is to alleviate her sadness and depression at being alone. She chooses to accomplish this by visiting a bar -- it's clear from this and earlier scenes that Sarah does not fit in in the world in which she finds herself living. This goal is interrupted by the plot when she overhears the television and her new goal becomes to seek help. Rather than alert the bartender to her dilemma she chooses to leave the bar and seek refuge elsewhere...most likely her home (but since Reese intercepts her immediately outside, she is forced to seek refuge in a nightclub).
These beats must speak to throughline, the "why" of the script, and story, the "what" of the script, because they are the "how" of the script. As you work on your screenplay/film/role you have to think of each moment in the story as it stands in relationship to the whole. This is very difficult, obviously, and is the reason it's best to work on screenplays in a group setting -- thus the birth of development hell.
One thing that connects these beats together and allows us to gain insight into character is something called "business." This is sometimes mistaken as "ticks" or "quirks," but I prefer to call this business and insist that my writers and directors call it that as well. The reason I do so is to emphasize the purpose of these story elements. I think ticks and quirks predispose a writer/director/actor to create odd characteristics (like nail-biting, or hair twirling) that fail to speak to theme or story. Business, on the other hand, is motivated by the needs of the given circumstances in a scene and directly reflect the throughline and story.
Really great actors reach for business instinctively (uncovering resonate bits through their training). It can be as simple as hiding behind a curtain of hair (especially if that hair and the act of hiding are metaphorically tied into the themes of the film and speak to the character's "secret" as in the fake blonde hair that Kim Basinger hides behind in LA CONFIDENTIAL -- hair that marks her as a Fleur-de-lys call girl, and a brunette masquerading as Veronica Lake). Or, it can be obvious as Jason Bourne's habit of flatly examining every aspect of the locations he finds himself in, which later is revealed to be his way of memorizing details that help him evade, detect or defeat his enemies, and achieve his goals and also reveal that he is, in fact, a super spy.
How does this help you write a better screenplay? Direct a better movie? Create a moving portrayal? By connecting business to the beatwork, to the story work to the throughline, a film can sing. Start with the big stuff in your first drafts and then work into the details. If you find yourself stuck or confused work from the big picture -- you may have a theme issue, or somehow the story you are telling isn't connecting back to your throughline. If you can find tons of business that feels right, but it doesn't seem to be leading back into your plotting, you may have a disconnect between plot and character. Character and plot are really the same thing, and the strength of the scene work is what shows you this.
Go. Get to work. I want my pages by Friday.