One of the challenges of writing the fact-based film is wading through the research, characters and historical detail to find the strongest screen story. To help you, our Writing the Fact-Based Film 101 series looks at how you can find and refine your central story thread.

What is the central story thread?

The central story thread refers to the main narrative or storyline which runs through the film. It is the core element around which the entire plot revolves. Usually, it centres on the main character and their primary goal. This thread informs the obstacles and conflicts the protagonist faces, before a resolution is reached at the end of Act Three. In most scripts, the central story thread is established, or at least introduced, early on in the narrative.

For example, writers Kelly Marcel and Sue Smith immediately set out the central story thread in Saving Mr Banks (2013). They show us the protagonist, author P.L. Travers, as a child with her father in Australia and then as an adult in London, expressing her reluctance to go to Hollywood to meet with Walt Disney, who wants to turn her book Mary Poppins into a musical. We then follow Travers to garish LA and find out why she’s so reluctant for Disney to adapt her beloved novel.

Central story thread vs. premise

While related, the central story thread and premise are different concepts.

Central story thread: As we’ve seen, this is the main storyline which runs through the film. It involves the primary characters, their goals, conflicts, and the overall trajectory of the plot.

For example, the central story thread of Saving Mr Banks might read something like: ‘British author P.L. Travers travels to Hollywood to meet with Walt Disney, who wants to turn her book Mary Poppins into a musical. Travers comes into conflict with the filmmakers over the changes they want to make to her novel, which, while fiction, really tells of her relationship with her loving but troubled father.’

Premise (or logline): This is a concise statement which outlines the basic idea or concept of the story. It encapsulates the core concept and sets up the narrative. The premise is usually the first stage of planning a screenplay, suggesting the trajectory of the plot and the possible conflicts which will arise.

For example, the premise of Saving Mr Banks might read something like: ‘A prim British author reluctantly travels to Hollywood to meet with Walt Disney, who is determined to turn her deeply personal novel, Mary Poppins, into a musical.’

Finding the central story thread

Sometimes, in a screenplay based on an episode from history, the central story thread is easy to find. An example is 12 Years a Slave (2013), which follows Solomon Northup, a free African American man who was kidnapped and sold into slavery in the pre-Civil War United States. Another is Erin Brockovich (2000), which centres on a legal assistant who investigates and brings to light a case of water contamination by Pacific Gas and Electric Company in Hinkley, California.

In both these examples, there is a narrow focus on a single protagonist, with the conflicts, story progression and relationships defined by the central thread. Northup battles to regain his freedom, while Brockovich balances her home and work life, all the while fighting to get justice for the Hinkley residents.

However, sometimes the central story is unclear. This might be because the material is too rich or concerns a life too full of achievement. An example is Lincoln (2012). Writer Tony Kushner’s first attempts came in at 500+ pages, covering the final four months of Abraham Lincoln’s life. However, the produced draft (based on Team of Rivals: The Political Genius of Abraham Lincoln by Doris Kearns Goodwin) refines this down to two months, spanning the process of passing the 13th Amendment, which abolished slavery, in an attempt to end the Civil War. From the lengthy source material, Kushner selected a strong central story thread, which starts with a scene on a Civil War battlefield and then moves on the show Lincoln in despair over the continuing war, which has stretched into its fourth bloody year.

A good way to start to finding a story thread is to think about the opening and ending, as you see them. These scenes generally mirror each other in some way, bookending the narrative. So, how do we meet your protagonist and where do we leave them? This will help to define the “bit in the middle”, where their life is dominated by a single goal.

Another way to think about the central story is the theme. Which parts of the story most interest you? A character’s struggle for freedom or fight for justice? Maybe it’s a relationship which is the most compelling aspect of the story and forms the heart of the narrative, such as in Maestro (2023). Who is the protagonist and what is their life really about? Figure out the theme and you can tailor your central story accordingly.

For example, the narrative of On the Basis of Sex (2018) spans around 20 years in the life of the late Ruth Bader-Ginsberg. Throughout, the central story thread remains focussed on her fight for gender equality, starting with her own experiences as a female student in the male dominated world of Harvard Law School in the 1950s and extending to the key 1970s case of Moritz v. Commissioner.

Finally, nothing beats research! The more you know about the background to your characters and their stories, the easier it will be to develop a central story thread.

Overall, the main word to keep in mind is “focussed”. Fact-based or not, a screenplay is essentially about one character who overcomes mounting challenges to get something they want. All the elements of the plot should feed into this journey.