Five years ago, Pablo Larraín impressed the world with his take on a lonely young woman struggling to remain sane within a terrifyingly rigid power structure. The parallels between Jackie, his study of John F Kennedy's widow, and this spaced-out fantasia on themes from Princess Diana's martyrdom hardly need to be further clarified. Yet there are different challenges here. Despite spending time as the world's most watched woman, Jacqueline Kennedy Onassis remained impressively unknowable to the outside world. There was an enigma to be conjured with. Almost none of us really knew Princess Diana either, but so plentiful were the analyses, exposés and confessions – her famous interview with Martin Bashir among them – that the average citizen may reasonably feel there is nothing left to be discovered.
Neither Larraín nor Steven Knight, his screenwriter, claim to be digging up new information here, but the film does take us to places unvisited by the sensational biographies, the cheapo documentaries and – never too far from one's mind – the expensive drama series on Netflix. That distinctiveness comes from a creative tension between director and writer. The story follows a stressed Princess Diana as she faces up to the hollowness of her marriage during a fraught Christmas with the in-laws at Sandringham in 1991. The narrative drifts from misunderstanding to mistreatment. Timothy Spall lurks as a sinister equerry with an apparent mission to keep Diana within the approved tramlines. Sally Hawkins plays an amiable dresser with an open heart. Jack Farthing is predictably straight-backed as a not entirely unsympathetic Prince Charles. Knight's script does not exactly rattle along like a Miss Marple, but the metaphors are bang on the nose and there is, particularly in the closing moments, a worrying tendency towards the girlboss school of history.
David Cronenberg made something agreeably odd of Knight's conventional screenplay for Eastern Promises. Larraín goes further still in magicking up an idiosyncratic nightmare from a script that could easily have generated something considerably more white bread. This is not to suggest the writer doesn't take risks. This is, after all, a film in which the protagonist shares space with the ghost of Anne Boleyn (a distant relative of the Spencers). But the Chilean director's hand is firmly on the tiller throughout. Here is an intensification of the Diana tropes into a nagging, Sloane-camp singularity. Bizarre variations disrupt the clean narrative arc. Jonny Greenwood's peerless score – moving from pseudo-classical refrains for the formal receptions to squealing free jazz for Diana's private meltdowns – adds one more irresistible level of disquiet.
None of this would be to any purpose if there were not a strong performance at the centre. Kristen Stewart is inspired casting as a woman on the brink of escape from a superficially comfortable prison. Who better to play a person remembered for her perceived shyness than the current maestro of hooded introspection? Stewart is to the socially uneasy brood as Toshiro Mifune was to the drenched battle cry. One occasionally senses her struggling with the impersonation, but that only adds to the aura of insecurity. She manages to be brittle without being hard. She balances trepidation with determination. The performance will almost certainly annoy as many members of the Diana fandom as it will defenders of the Windsor orthodoxy. That is how you know you are doing it right.
Yet you couldn't call Spencer any sort of rebuke to the establishment. Shot largely in Germany by Claire Mathon, who did such good work on Portrait of a Lady on Fire, it offers a version of the royal residence closer to an ice palace than a Ruritanian idyll. But Queen Elizabeth, given just one line of dialogue, emerges as a wry sage. There are no confirmed monsters here. The protagonist comes from a background at least as grand (some snobs would say more so) than her forbidding hosts. If the names were not familiar we could imagine it a terrible fairy-tale. Set at Christmas. Hang on, is Spencer a Christmas film?
Opens on November 5th