Her heart-breaking and -mending story is one thread of Summer’s connection through Smith’s bravura seasonal quartet, written swiftly – on the wing – profoundly responsive to the news that rolls in, folded or scrolled, with its continual toll and knell. Hannah is the sister of Daniel Gluck, a character central to Autumn (2016) and now to Summer. In Autumn, Gluck is the elderly German-born neighbour who, amid ‘a fraction of something volcanic’ – Brexit, xenophobic graffiti, news of war, and environmental destruction – meets the young Elisabeth. Exchanging solace and reading, they set out to become lifelong friends: ‘We sometimes wait a lifetime for them’, as Daniel says in Autumn.

Now aged 104, Gluck is in lockdown while the pandemic flares – ‘one more time we’ll find out what’s worth more, people or money’. His thoughts drift to his internment with his father in a British camp for ‘enemy aliens’ during the 1940s. These Germans are ‘mostly Jews and people the fascists want dead’, Daniel tells a soldier who calls them Nazis: ‘We’re not Nazis … you couldn’t get more opposite from Nazis.’

There’s the flickering Zelig, traumatised Dachau survivor and ‘ghost brother’ to Cyril (‘partly doctor, but of course ejected from university’). And Maryan Rawicz, half of the celebrated piano duo (his musical partner is interred in another camp), searching for notes in the camp’s smashed and rattled pianos, their elephant-shorn keys torn out for dentists to transpose into human mouths. There are specialists on Rilke’s poetry, philosophers, and artists, including Kurt Schwitters, derided by Hitler as a ‘degenerate artist’, all severed and displaced.

Schwitters invented Merz art when he fractured the bank name Commerzbank and placed it in a collage. Merz rises from the smithereens of consumerism, bringing the discarded and broken into conversation with one another, including, in Summer, green-leaning porridge and the contents of his chamberpot.

The internees debate art. There’s a wink from Smith, whose own collage-like work might be imagined as Merzroman, when Daniel writes to his sister in a letter he then burns: ‘Should The Artist Portray His Age? ... And you would be so proud of me because I spoke up and said but what about the artist portraying her own age, and when I did I was nearly laughed out of the room’.

In Germany, Hannah is engaged in the exquisite midwifery of delivering names of the dead to save other lives. She takes her own, ceremonially, from the grave of Adrienne Albert, a girl born when Hannah was but who died as a child of Spanish influenza. In this delicate transmutation, life folds into life, ‘as metamorphic as caterpillar and butterfly’. Hannah invents a profession for Adrienne. She is a seamstress.

Something sparks – kinetic, molecular, anagrammatical – when Hannah gently transplants the names of the too-soon dead. She mentally continues the siblings’ conversation. In her brilliance – a swift, skip-quipping linguistic deliciousness that is Smith’s joyous imaginative signature – Hannah zips ahead of her thoughtful brother, lighting things up, stitching them. ‘She forgot. He is not flippant like she is. He is not quicksilver. His energy is steady, something like a tree root.’ His deep steadiness and her blossoming ingenuity are of the same tree.

Smith witnesses the risky trickery by which Hannah outpaces her hunters, crossing languages and borders. Translation for Hannah is both a wordsmith’s joy and essential to her survival. Amid all this appears Claude, also devoted to life and the resistance of violence, opening a new stanza for her (because, as Smith writes, drolly, ‘love happens’). In a park ‘overrun with flowers’ she waits, holding a copy of Rimbaud’s Illuminations. She meets his single word ‘yes?’ with her own: yes. He is a mimic who gives her the gift of her own laughter. He warns her that it’s easy to conceive when you are laughing, sparking the slant rhyme of laughter and daughter.

Claude and Hannah know they can’t have one another’s names in their head. Eventually, ‘she can’t have her own child’s name in her head’. The seams between loss and gain, the heartleap of all this, is where Smith is at her most magnificent.

Smith’s work spirals and vaults through ideas, texts, and fascinations: inclusive, allusive, empathetic. It works at the porous borders between singular and plural selves, and between syllables and languages. Its currency is quicksilver, its methodology crossing, as metaphor’s is (arriving, as it does, from the Greek metapherein, to transfer), and translation’s (from the Latin, translatio, to transfer).

In Spring (2019), a mysterious, heroic young woman – Smith’s portrait of a kind of Greta Thunberg – imagines: ‘instead of saying, this border divides places. We said, this border holds together two really interesting different places. What if we declared border crossings places where, listen, when you crossed them, you yourself became doubly possible.’ And Charlotte (returning from Winter [2017]) reminds Sacha: ‘A chance to make the world bigger for someone else. Or smaller. That’s always the choice we’ve got.’

Instead of the pernickety exactitude of borders, passports, ego, and linear narrative, Smith’s work is echoic, prismic, full of siblings and doppelgängers, and that intake of breath when someone enters a life carrying the echo of someone else’s beauty, as when Daniel sees Hannah in Sacha.

Each of the quartet’s novels has a Shakespearean play spun through it, in this case The Winter’s Tale. Sacha’s mother, a former actor, sees the play as ‘all about summer, really. It’s like it says, don’t worry, another world is possible.’ This renewal is central to Schwitters’s art, of which he said: ‘everything had broken down and new things had to be made out of the fragments’. Virginia Woolf – her work a kind of heartland for Smith – had a similar idea: ‘arrange whatever pieces come your way’.

After the war, Romanian-born poet and Shoah-survivor Paul Celan wrote: ‘Only one thing remained reachable, close and secure amid all losses: language. Yes, language. In spite of everything, it remained secure against loss.’ Amid loss and trauma, a poem goes out, a ‘message in a bottle, sent out in the – not always greatly hopeful – belief that somewhere and sometime it could wash up on land, on heartland perhaps’. As Hélène Cixous wrote of Celan’s poems, they take ‘the desert as subject ... It is a writing of disaster, a writing that speaks of and through disaster, such that disaster and desert become the author or spring.’

Summer begins like the other three quartet novels with a soaring monologue, strung from that embodiment of apathy: So?

As in so what? As in shoulder shrug, or what do you expect me to do about it? or I so don’t really give a fuck, or actually I approve of it, it’s fine by me.

But no, there is a swerve from this certainty. ‘Not everybody said it.’ Like Hannah the seamstress, like Schwitters, Woolf, and Celan, Summer says, instead, sew.

So, to the seam where swifts flock with larks. Through the abundant generosity of her allusions – to film, photos, poetry – Smith’s novels carry ideas across borders. Sacha’s summer-opening, summer-carrying lark summons whatever larks we might have in the private treasury of our own heart’s sustaining images. I hear Dickens. Not his novel David Copperfield, which circles through Summer, but the orphaned Pip in Great Expectations embraced by his generous uncle-by-marriage Joe, who declares of their adventures ‘What larks, Pip!’ I think of Woolf’s Clarissa Dalloway, newly recovered from the Spanish flu, tenderly opening the day: ‘What a lark! What a plunge!’

I remember larks that cross the river in Alice Oswald’s Dart: ‘listen / a / lark / spinning / around / one / note / splitting / and / mending / it’. Smith’s quartet is a work of splitting and mending, repair instead of despair. Hard-won creativity trumps the graspers and bruisers. Unafraid of being laughed out of the room, the larking, migratory powers of the heart – kindness, love – compose the notes of revival, as recuperation and gain surge up after violence and loss, tendrils, as summer does.