The world​ is often just about to end in Sarah Hall’s fiction. In The Carhullan Army (2007), England is in a state of political and ecological collapse. ‘You don’t believe the world can really be broken or that anything terrible will happen during your lifetime,’ the narrator reflects. But the unimaginable soon begins to feel inevitable: ‘You just know when the world is about to break apart. I think you just know it, don’t you?’ In Burntcoat (2021), a plague narrative written during the Covid pandemic, the main character, Edith, rebukes herself for her lack of foresight: ‘We live temporally, deluded. Not here, not us. Of all people, I should have known better.’ Hall told an interviewer at the time that she has a bookshelf devoted to ‘government contingency planning, disaster mapping and management’.

Hall’s characters like to weigh up the benefits of resistance. In her short story ‘Then Later, His Ghost’ (2014), a ferocious wind that had been ‘kept in check by the old Gulf Stream’ is set loose by climate change to ransack towns and whisk the sea into surging waves. To surrender to resignation, the narrator knows, ‘would be the beginning of the end’, and yet the appeal of ‘crawling into a calm little shelter’ is hard to shake. The protagonist of Hall’s latest book is the wind itself. Helm, the only named wind in the British Isles, blows through Cumbria’s Eden Valley, where Hall was raised and where much of her writing, including The Carhullan Army, is set. The novel opens ‘in the beginning’ when ‘there was no Helm.’ Its origins – when Helm was ‘brewed’ or ‘conjured’ or ‘conceived’ – are unclear. The wind whizzes through the ‘billennia’, witnessing waves of ‘mass extinction’ and, eventually, the arrival of humans. These ‘up-monkeys’ intrigue Helm, who watches them scavenging, ‘skirmishing’, ‘reproducing’ and ‘carking it’. Like the wind in ‘Then Later, His Ghost’, Helm is now threatened by climate change. It’s ‘the surprise disease on the routine tests’.

Anthropomorphism is familiar territory for Hall. In ‘Mrs Fox’ (2013), for which she won her first BBC National Short Story Award (she is the only writer to have won it twice), a woman becomes a vixen. In an interview Hall recalled trying to make the metamorphosis seem believable: ‘At what moment does human bone become fox bone? How?’ The surreal sets in slowly: first ‘something is wrong with her face’, then her lashes thicken, her teeth shrink and her bones are recarved, until eventually ‘all vestiges’ of the human are shed. We suspend our disbelief by degrees until we’re eye-to-eye with a fox. In Helm Hall is less cautious. The wind’s ‘coming of age’ is rapid and the ‘existential dilemma of who/what/why’ happens in an unsettling rush: ‘Helm enjoys the feeling, of agency, of urgency, so plays with Helmself to arouse the feeling: desire for great, wreaking, havoc-making release, surging from a sky-orifice, down the mountain and – yes, yes, oh yes, there’s Helm.’

There are other – human – voices in the narrative, as a procession of characters engage with Helm over the millennia. They range from the Neolithic to the Victorian, from a medieval priest to a 1950s schoolgirl and a modern-day climate scientist. In the earliest of the subplots a young girl called NaNay sets out to prove to her tribe that she is a seer: taking on Helm is a way of testing the power of her visions and prophecies. Later characters attempt to subjugate or domesticate the wind. Helm took Hall twenty years to write. She seems to have stockpiled characters along the way, and is now keen to deploy them all in one go. In their respective chapters, they emerge with a remarkable array of foibles, histories and contradictions. There’s Michael Lang, the Dark Age wizard priest, tasked with exorcising the valley of its ‘aerial sovereign’. He condemns in others a susceptibility to sin (‘All are weak vessels waiting to be filled’). He also finds his own vulnerability ‘intoxicating’ and, when his slave washes him, the ‘reversal of control arousing’. There’s Dr Selima Sutar, a ‘cloud pollution’ scientist stationed in a remote observation hut, who thinks about cigarettes as much as about end times and ‘airborne polymers’. She enjoys the ‘cool carpe diem of secret transgression’. Her smoking is all the more subversive, it turns out, because her father treated patients with emphysema. Even Thomas Bodger, a hapless 19th-century scientist who has promised the newly chartered Royal Meteorological Society ‘an answer to Helm’s mysteries’, has hidden depths. His wife is ill, and in her absence he develops a chaste crush on her standoffish cousin, whose alcoholic husband dies in mysterious circumstances.

Some of these subplots are revisited sporadically as the novel progresses; others (like a vignette about an adventurous couple in a hot air balloon) stand alone. Occasionally the episodes have the elliptical promise of Hall’s short stories, but more often they seem incidental. Human drama shrinks to the frantic, fervent misadventures of ‘soap opera’, what Helm calls ‘the exceptional theatre down there, where the actors love and despise each other, help and betray each other, break whatever they’ve made’.

Helm has a predecessor in Richard Powers’s The Overstory (2018), another polyphonic work of ecofiction that spans generations and distorts chronologies. In The Overstory, it’s trees that are at risk. Patricia Westerford, a dendrologist, discovers that they share ‘a common ancestor’ with humans and can signal to other trees in ‘elaborate vocabularies’. Her findings are initially dismissed. She retreats to the forests, where – high on Thoreau and the righteousness of her cause – she gives thanks to the trees: ‘Thank you for the baskets and the boxes. Thank you for the capes and hats and skirts. Thank you for the cradles.’ When she’s later called on as an expert witness in a hearing about logging on federal land, her research spills out in a homily on the ‘tied-together’ lives of humans and nature. ‘It could be the eternal project of mankind,’ she declares to a circumspect courtroom, ‘to learn what forests have figured out.’ But The Overstory also has a more disturbing take on this ‘project’: activists become arsonists and Patricia considers killing herself on stage during a speech to set an example of the ‘single best thing a person can do for the world’. Hall is less interested than Powers in the practicalities of environmental resistance, but she goes further in exploring what the voice of a natural phenomenon might sound like, and what it is that we can learn from it. The kind of prosopopoeia she attempts is difficult to sustain, however; Helm’s voice becomes wearing and often cracks.

Like The Overstory (and much ecofiction), Helm is keen to show us the error of our ways. Selima’s research into microplastics has belatedly become ‘mainstream news’. The polymers are already everywhere: ‘In the water, the soil, in fish and vegetables, her teabag. In the bloodstream, the testes, perhaps even the brain.’ Even so, Selima’s detractors, the ‘Endtrepreneurs’, incensed by her appearance on the Today programme, send anonymous messages ‘about the few and the many’ in the apocalypse ‘and something about Babylon’. The messages are laughable at first, then sinister. As Selima notes, ‘anthropocene destruction and eschatology’ are ‘not dissimilar’. The Endtrepreneurs bombard Selima with cryptic threats while she studies ‘real-world problems’, the way ‘heat, radiation, pollution’ will ‘fuck up all the norms in this little kingdom’. The question is which will come for her first – the Endtrepreneurs or environmental catastrophe?

What’s unusual is the optimism Hall maintains. In a recent essay for the Guardian, she claimed that, in the process of writing Helm, she had come to think it was the writer’s responsibility to ‘imagine ways up and out of doom scenarios instead of just describing the conflict within them’. Something of this new-found positivity seeps into the later parts of the novel. People are suddenly swept off their feet by Helm or overawed by its presence. When Janni, the 1950s schoolgirl, returns sedated from a psychiatric hospital, it is Helm that rekindles her emotional life. She is overcome with ‘all the lover’s sensations’: ‘Nothing moves and no one denies her and there’s no sound other than Janni’s mouth kissing and kissing and kissing the air.’ A similarly bewildering communion occurs when Jude, a gruff, traumatised policeman turned glider pilot, flies through Helm. He feels like a ‘comet’ as he soars ‘up above the world’ and ‘away from its hold’. On the page, his thoughts give way to a riot of rapturous dashes:

It is gorgeous, it is –
the opposite –
of what might have been –
if he’d jumped from the bridge and ended –
Hope, love, ecstasy, God, if there is a God, oh God, it is so –

All of this is uncharacteristically sentimental for Hall. But some of her dark, deflating style survives. When Jude relates his ecstatic experience to his wife, she makes him feel ‘like a tosser’. Even Selima, the perfect ‘rationalist’, begins to have hallucinations. One evening she leaves the field station convinced ‘the worst scenario is not happening.’ But, as the wind gets up, it dawns on her that ‘something awful is going to occur, something violent and tragic; it’s not possible to stop it, it’s never been possible.’ Increasingly disorientated, Selima gets lost in an entropic haze. But she remains stoic. ‘It will all be funnier in the retelling,’ she thinks. ‘How a group of New Pagans, dressed in green velvet cloaks, antlers and bird masks found her’ alone by the road, ‘gave her hot tea and chocolate biscuits in their camper van’ and carted her off to the police station to be collected. Whether this unlikely rescue party ever arrives is unclear.