If Ladies of Steel is anything to go by, Finnish songs are extraordinarily gloomy. Birthday songs, love songs, patriotic songs, songs of celebration: they are all as miserable as sin.

And yet, the nation has a knack of producing strong comedies and Ladies of Steel (available until 21 June at 19:30) is one of those. Old people in films are either the butt of jokes or they are feisty battlers, especially the women. Here, three elderly sisters set off in an elderly Mercedes after one of them does something terrible. There are jokes at their expense, and they do a bit of battling, but mostly they argue, compete and commiserate with each other, a microcosm of their own in a world that is happy to ignore them.

The film opens with Inkeri digging a deep pit in her garden. Under her coffee table lies a man. Very soon it emerges that this is her appalling husband, Tapio. She has hit him with a frying pan and goes to her sisters for advice. One, Raili, is either a lawyer or fancies herself as one. “Teflon or cast-iron?” she asks. “Teflon,” replies Inkeri. “That’s manslaughter,” says Raili.

The three – the third, Sylvi, is a timid innocent, at least until she gets some vodka in her – head off to the police station, working on Inkeri’s defence as they go. But there are diversions, and they never make it. Inkeri wants to go to the university to find proof that she once was a student there. She finds more than that; she learns she was a feminist and radical called Free Girl, and is briefly fêted by the new generation of liberals, an encounter that proves bewildering for all parties.

Inkeri’s youthful radicalism – “there can be no capitalism without patriarchy, and no patriarchy without capitalism” – is roundly mocked by Raili, a worldly-wise veteran of five marriages, who chain-smokes and wears fur. “It was wise of you to stop studying,” she snaps. “That’s total bullshit.”

Later on, they pick up a young hitch-hiker and Raili sets her sights on him. “He was undressing me with his eyes,” she claims. Then they all reach a motel, and it is mild Sylvi who, unaccustomed to drink, ends up sleeping with him. When she wanders around the corridors next morning, half-dressed, and gives some fellow guests a view they hadn’t expected, the humour momentarily drops through the floor. The film is unsparing about the physical depredations of age.

Otherwise, though, the dialogue is sparky and the three ladies are good company. There is no end of casual cruelty – “you were starved of oxygen at birth” says Raili to Sylvi – but they do need each other.

Later, while Inkeri and Tapio’s stressy daughter Maija tries to organise an extravagant birthday party for her mum, the three find refuge in their old family home. There, Inkeri ponders her first love in soft focus, but finding him again after 50 years does not prove uncomplicated. He and his new partner welcome her to join them in naked dancing, dope smoking and poetry reading, but when they learn about the reason for her flight they threaten to call in the local policeman.

In her parents’ house, Inkeri finds the novel she wrote as a teenager. Raili has a view on that, too, and it is predictably bracing. “Two hundred pages of sentimental crap,” she says, but a few very arousing sex scenes.”

The plot ends with a party, although not the party Maija had planned, and some embarrassing revelations. There are also songs. Sad ones.

Ladies of Steel is available until Sunday 21 June at 19:30. Details here: https://ciff.shift72.com/film/ladies-of-steel-terasleidit/