Riddled with an effortless charm and sprinkled with a hint of misery, Kristen Stewart as the late Princess Diana in Spencer is everything you want in a dramatic retelling.

Aside from witty dialogue, astonishing cinematography, and a breathtakingly transformative performance by Stewart, the film delivers a beautiful portrait of perhaps the world’s most beloved historical figure. 

It's set during what was a real-life moment in time; the Princess of Wales would spend Christmas with the royal family. During our interview, screenwriter Steven Knight explained that this story was not a conventional biopic — they are "impossible to do well," he said — but something more: an attempt to capture Diana’s emotional essence. 

"I wanted to focus on the shortest amount of time possible and really put the focus on Diana," Knight said.

"This isn’t a story about the royal family. It’s about her interactions with them." 

Thus, most of the scenes are not verbatim portrayals, but re-imaginings of pieces of truth that Knight and director Pablo Larraín stitched together.

"I was able to speak to actual staffers who were there during that [Christmas]. From there, I sought to tell a story of who Diana was emotionally at that time, rather than a series of plot-driven scenes," Knight said.

The film opens with a devastatingly charming Diana asking a townsperson for directions to the royal family estate, as she’s opted to leave behind security and drive herself to the annual Christmas celebration for the first time in almost 10 years.

When she arrives, it’s clear that not only is she suffering from an eating disorder, but her marriage to Prince Charles is beyond repair. Diana’s only light during the course of the one hour and 57-minute film are her sons, William and Harry.

In an interesting choice of subplot during the second act, Diana is mysteriously given the biography of Anne Boleyn and becomes obsessed with the similarities between herself and the tragic former queen; two women with parallel lives, one of which is most desperate to not become the other. 

"Anne Boleyn has a tragic love story, similar to Diana’s," Knight said. 

"She’s killed by her husband for not bearing a son, while Prince Charles’ relationship with
Camilla was widely known at that time." 

Knight's decision to include Boleyn was an extension of his research, which seeded into the script.

"I learned that the Spencers were distant relatives to the Boleyns like, the idea that Diana feels like she’s haunting the palace already," he said.

Making decisions like this one gave Knight an overall sense of freedom with the script.

"After Pablo and I both agreed we wanted to make a movie about Diana from a concentrated
space, I just started writing," he said. 

"There were moments when I would write a scene and go, 'Where did that come from?' I wasn’t tied down to traditional story elements, so a lot of the story just came rather quickly. It just worked. So much so that the film you see onscreen is what it was in the script. For a feature to have that happen is very rare."

The film ends — spoiler alert — happily for Diana; she escapes the palace with her children and eats fast food. According to Knight, this ending, much like writing the project, was a perfect fit.

"There’s something about a project that just comes together organically," he said. 

"The script fell together in a matter of weeks. There were no studio execs on conference calls telling us what we could or could not do. There wasn’t even any rewriting, really. I finished the script and gave it to
Pablo and he did what he does." 

Spencer is now playing in theaters.