Two women talk for the best part of three-and-a-quarter-hours and Ryusuke Hamaguchi makes of it an unassumingly momentous miracle. “All of a Sudden,” the Japanese director’s gorgeous new feature, is the rarest type of film, not merely good enough to remind you what cinema can be, but great enough to remind you what life can be. At times, suspended in the long silvery skeins of conversation that thread through the magnificent screenplay (by Hamaguchi and co-writer/translator Léa Le Dimna) it achieves a kind of levitating grace, before depositing you back down in your seat again, a slightly different, slightly mended version of the person you were before.

Marie-Lou (Virginie Efira) is one half of the film’s radiant heart, though there is nothing half-hearted about her. The recently appointed director of a Parisian home for the elderly, she is a crusader for Humanitude, a pioneering approach to care work, which aims to restore to elderly patients the dignity that a chronically under-resourced healthcare system regards as a luxury. But the transition to its methods is not all smooth sailing. Head nurse Laurence (Marie Denarnaud) and popular recruit Djibril (Gabriel Dahmani) are on board, while brisk, well-respected senior nurse Sophie (Marie Bunel) sees it only as an inexcusably indulgent added burden on the overworked staff. Initially it seems like the film will be a forensic examination of the politics of this institution (it was shot in a working care facility), with the battle lines between idealism and pragmatism thus drawn. And it is, but it’s about to be so much more.