Apichatpong Weerasethakul has returned to Cannes with his first substantial feature length work since the 2010’s Palme d’Or-winning Uncle Boonmee Who Can Recall His Past Lives. This is another of his unique imagist cine-poems: an essay in psychogeography and a meditation on death, the presence of the spirit world in nature and the unquiet ghosts of guilt and pain in the Thai nation, as symbolised by the military - a recurrent trope in his work.

Cemetery of Splendour has that unmistakable blend of an almost clinical reality and rationality with spirituality and mysticism. There is no incidental music; ambient noise is generally limited to cicadas and scenes and characters are shown largely in medium and long-shot, speaking evenly, and unemphatically framed and composed.

The story in some ways echoes his 2006 movie Syndromes and a Century. A group of soldiers employed in digging up a building site for a government project has fallen ill with a mysterious kind of sleeping sickness.

They are being cared for at a temporary hospital building which seems oddly open to the elements. Keng (Jarinpattra Rueangram) is a young volunteer at the hospital who has the powers of a medium – she says the reason for the soldiers’ condition is that they have disturbed an ancient cemetery of kings. The spirits of the dead are siphoning the soldiers’ energy; hence their narcolepsy.

Keng befriends Jenjira (Jenjira Pongpas Widner) another volunteer, caring for Itt (Banlip Lomnoi, from Weerasethakul’s 2004 film Tropical Malady) who like the rest of the soldiers becomes a living ghost, channelling the presence of the departed kings and their world.

Keng and Jenjira become friends, and Jenjira confides to her a relationship with an American – but teasingly claims she would rather be with a European because they are richer – and finally opens up to Keng about an agonising and mortifying disability in her leg. But Jenjira is also, startlingly, visited by the spirits of two Laotian princesses who appear naturally and calmly: dressed as mortal women.

Weerasethakul combines a gentle deadpan humour – some of the nursing attendants gigglingly touch a sleeping soldier’s erection – with his usual quietist worldview. If the sleeping sickness is a form of group hysteria, then it is a very calm sort of hysteria. But more than this, it is another example of this director’s insistence on a spiritual realm which overlaps with our own: a realm from which ghosts and spirits will appear, and be just as ordinary as anyone else. And in this context, Jen’s own loneliness and gentle spirituality are deeply affecting. It is such a strange film in its way, stranger still if you are not accustomed to Weerasethakul’s work, and it needs a real investment of attention. But there is something sublime in it.