Princess Diana appears to be in constant motion in Pablo Larran’s Spencer. She’s scurrying along elegant corridors, creeping across lawns in the dark, and sprinting across fields. The video depicts Diana anxiously seeking to leave the claustrophobic constraints of the Royal Family, which feel even tighter than usual because the entire family is imprisoned in Sandringham Estate for the Christmas holidays.

Spencer describes it as “a story based on a historical tragedy,” and Larran and screenwriter Steven Knight reinvent a Diana who might have been. It’s December 1991, and Diana and Charles’s relationship is strained, partly due to his continued affair with Camila Parker-Bowles and partly due to the attention she receives from the paparazzi and the public as a whole.

Of course, Diana’s life has recently been fully addressed in The Crown and Diana: The Musical, a stage performance available on Netflix. Spencer stands out because it concentrates on a few days to give viewers a glimpse into Diana’s stressed thinking as she tries to navigate royal life. Kristen Stewart’s Diana is not the modest, young preschool teacher whom Charles chose as his bride, but a woman on the edge of unraveling after many years in the Royal Family.

Diana is first seen on her journey to Sandringham Estate, where the family will spend many days celebrating Christmas. She chose to drive herself and ended up getting lost, which is certainly a metaphor for how she feels about her life as a whole. Her revelation that Sandringham is close to the Spencer family home where she grew up will torment her for the next few days, as she can’t shake the temptation to return to the house, now in disrepair, possibly in the hope of finding some of the peace she once knew.

Stewart provides a superb performance as Diana, who is succumbing to delusions that are masterfully played out onscreen. Diana not only suffers from bulimia, but she also develops a crush on Anne Boleyn, another royal woman whose husband had an affair. Diana’s association with such a sad individual, who died at the hands of the Crown, demonstrates how imprisoned and defenseless she feels.

Stewart is no stranger to public criticism, so it’s hardly surprising that she can paint such a nuanced portrayal of Diana. It’s hypnotic to see her entirely vanish into the part, which never feels like an imitation of Diana, but rather a full-fledged character in her own right. Stewart is able to convey so much to the audience through her eyes, facial expressions, and tone of speech that we are completely immersed in her inner world.

Diana connects far more easily with the staff than with the Royal Family, some of whom serve as lifelines for her. Maggie, Diana’s Royal Dresser, is played superbly by Sally Hawkins, who bolsters and coddles her when she requires it. Sean Harris plays the Royal Head Chef, Darren McGrady, who is a similarly stabilizing influence for Diana, delicately keeping her back on track in between creating lavish extravagant dinners.

Diana, on the other hand, clashes with Equerry Major Alistair Gregory, played by Timothy Spall, who has been hired to supervise the trip. He’s a mysterious figure, and Spall does an excellent job of expressing a British rigidity while still demonstrating his changing feelings about the princess.

Diana’s two kids, William and Harry, played by Jack Nielsen and Freddie Spry, are her greatest joys in life. Stewart has great interaction with both of the boys, who are charming, and the sequences with them help to anchor this otherwise strange picture. Nielsen, on the other hand, does an excellent job of depicting William’s lingering uneasiness, as he has a greater comprehension of the situation than his younger brother due to his age. The viewer sees a different side of Diana with her sons, but we also get a sense of the strain Diana’s problems had on William in particular.

Spencer’s craftwork is excellent, in addition to being flawlessly directed, written, and played. Jacqueline Durran’s costumes and Guy Hendrix Dyas’ production design are stunning, creating a gilded prison for Diana’s life. The rich food in the film also contributes to the creation of this atmosphere of excess. Claire Mathon’s cinematography is stunning, and the rare use of a shaky handheld camera helps to immerse us in Diana’s collapsing mind.

However, Jonny Greenwood’s score stands out as the most amazing effort. The juxtaposition of highly stately classical music with a jazz influence generates a cognitive dissonance reminiscent of Diana’s status inside the Royal Family. Throughout the film, the music helps us grasp Diana’s emotional state.

Spencer is a disturbing depiction of a lady on the verge of collapse, desperate to escape the Royal Family’s suffocating atmosphere. It’s a moving memorial to Diana, but it’s also an insightful statement on the affluent, but toxic society that has emerged following Prince Harry and Meghan’s departure from Royal life. Stewart provides her strongest performance ever, but she’s not the only appeal; Spencer is one of the best-made films of the year.