Here is a stylish and exhilaratingly confident debut from 39-year-old Thai film-maker Ratchapoom Boonbunchachoke, which won the critics’ week grand prize at Cannes last year. It is a supernatural black-comic fantasy of national grief executed with passion and panache, about the ghosts who have refused their afterlife confinement after the country’s succeeding catastrophes: the bloody results of a military crackdown in 2010, coup d’etats in 2006 and 2014, and before them, the 1976 Thammasat University demonstrations, along with loved ones that went to an unquiet grave of their own.

A Useful Ghost is heartfelt and elegant in its compositional flair; dreamlike tableaux are crisply juxtaposed in the edit and the whole effect is disquieting, erotic and terribly sad. It’s in some ways a humorous twist on the serious spiritual realities laid out in the movies of Thai master Joe Weerasethakul, like Uncle Boonmee Who Can Recall His Past Lives and Cemetery of Splendour. And you might also sense the spectral shimmer of western films like Ghost and Truly, Madly, Deeply.

Boonbunchachoke envisions a Thailand which is vigorously effacing and pulverising its inconvenient past; roughly removing, for example, a frieze from Bangkok’s 1940 Democracy Monument, creating clouds of metaphorical toxic dust. A queer academic (Wisarut Homhuan), writing a paper on the iconography of this frieze, is astonished when his new vacuum cleaner starts coughing up the dust it has only just inhaled. Repairman Krong (Wanlop Rungkumjad) who arrives with eerie speed after his phone call to customer services, tells him the problem is that the factory which made the hoover is haunted … and we flashback to the strange story he has to tell.

A worker called Tok (Krittin Thongmai) haunted this factory as a poltergeist after he collapsed on the shop floor due to ingesting poisonous dust. And the bad karma extends to the factory owner’s own family: Nat (Davika Hoorne), the young daughter-in-law of the owner’s widow Suman (Apasiri Nitibhon) died in childbirth due to dust inhalation and she returns to invade one of the factory’s vacuum cleaners; it comes to life and tries to have sex with her grieving husband March (Wisarut Himmarat) who is poignantly ready to have this consolatory contact. But Nat’s ghost is prevailed upon by Suman and then by government minister Dr Paul (Gandhi Wasuvitchayagit) to make herself useful to the state by invading the dreams of workers who are keeping all sorts of commercially and politically inconvenient ghosts alive by remembering them.

Suman has to get these undesirables forgotten again – she is the ghost in the machine of repression, a ghost who the machine itself tries to turn against all the other ghosts. And there is something deeply troubling in the way Nat’s ghost can be “turned” by exploiting her yearning to have a baby, even in her own ectoplasmic state. Without the written permission that would otherwise be necessary, her widower is told he can use the eggs she had frozen for this purpose, and Nat’s ghost is presented with a macabre “death day” gift at the minister’s luxurious modernist home. It is a movie with flesh-and-blood intensity.