The young girl in the painting is running towards us through an overgrown spring garden, its trees heavy with dazzling white blossom. Behind her is a bombsite – this is London in March 1950 – also overgrown. Other children are crouching among the bushes and the long grass, hunkered down behind the low garden walls, but the girl has seen none of them. Only we, looking down on the scene through the eyes of the artist Tirzah Garwood, who by now is terminally ill, can see everything. In fact, she has a year to live.

The painting is the first you see in the last room, dedicated to that last year of Garwood’s life, in Tirzah Garwood: Beyond Ravilious, the new exhibition of Garwood’s work at the Dulwich Picture Gallery in south London. It is titled Hide and Seek, and it seems to articulate some key themes in her art: in particular, the sense of childhood games as both a metaphor for life and a tool in the search for its hidden meaning, and of the perceptible world as a theatre for imaginatively intense exploration.

That sense of revelation and discovery in her work is surely heightened because the work itself has remained largely hidden from view for so long. Garwood is best known today, if at all, as the wife of Eric Ravilious. Despite appearing in a couple of smaller exhibitions at the Towner Gallery in Eastbourne and Bedford’s Fry Gallery over the years, her work has had little public profile. Almost all of her pieces are in private collections. Although she was at times highly praised in her lifetime, her early death at the age of 42 propelled her into an unearned oblivion; the last time much of her work was gathered in one place was at a memorial exhibition in 1952. The Dulwich Picture Gallery then is hoping to re-establish Garwood’s name with this show, which has been curated by James Russell, who was also responsible for the gallery’s 2015 and 2018 trailblazing exhibitions dedicated to Ravilious and Edward Bawden respectively.

They surely will succeed: this is a remarkable body of work shaped by a distinctively English early-20th-century imaginative vernacular and aesthetic. It is a world of dog shows and harvest festivals, of vegetable gardens and trains, of ice-cream carts, quiet domesticity and bourgeois villas, and lots and lots of toys. And yet, for all the immediate sweetness and charm of Garwood’s work, the further you enter into its domain, the more you appreciate its strangeness, its meditative intensity and precision, its deep sense of play, and its powerful interiority. The whole exhibition is a kind of walled garden; even as it looks outwards, Garwood’s art dives deeply inwards. Apparently solid, comfortable realities dissolve to reveal, paradoxically, a dense, hypnotic quality of hiddenness. Everywhere we feel ourselves to be intruders on a private mythos. You won’t have seen anything quite like it.

She was born Eileen Lucy Garwood in Gillingham, Kent in 1908; Tirzah is a family nickname that stuck. The family later moved to Eastbourne and it was there, in 1926, that she met Ravilious while studying at the Eastbourne School of Art, where he taught her wood engraving. Her second effort is reproduced here: a large, middle-aged woman and her West Highland terrier battling into the wind across an open field. Her gifts are immediately, precociously apparent. From the beginning she liked playing games with shape, perspective, and scale: an early wood-engraved self-portrait has her admiring her full-length reflection in a funhouse hall of mirrors.

She and Ravilious married in 1930, not entirely with her parents’ approval: Garwood’s family were officer class; Ravilious’s father was trade. A 1928 engraving titled Cat into Woman suggests she may have had her own anxieties about matrimony: it shows a cat transforming into a naked woman at the feet of a man in an oppressively cluttered sitting room. An engraving from the following year, The Wife, is a self-portrait, sat upright in bed. Above her head is a painting of a house. You half imagine there is another woman sat upright in the bedroom of that house, too. And so on, endlessly. As was typical in the period, Garwood was expected to run the home, and that curtailed her ability to work on her art. ‘Working’, she later wrote to a friend regretfully, ‘is difficult with a house to think about.’ Nevertheless, she persisted. Her work in the early thirties revolved around wood-engraved pattern papers for a number of publishers, but later in the decade she mastered the art of paper marbling, producing work of such quality that the V&A was compelled to buy some examples in 1937. Their lives became increasingly rural. They lived part-time at Great Bardfield in Essex with Edward and Charlotte Bawden; then later at Castle Hedingham, also in Essex. She and Eric both had affairs, but it seems to have been a mostly happy marriage nonetheless.

By the time war broke out, the couple had two young children. Eric was commissioned as an official war artist, and a third child was born in 1941. Garwood had already had a lump removed from her breast the previous year, but in 1942 she had to have an emergency mastectomy. In September 1942, Eric was lost at sea off the coast of Iceland.

The next phase of her creative life, begun in 1944, is marked by a turn to oil painting – a medium Ravilious disliked – and experiments with leaf-prints and collage that point the way forward to her later work. Her quality of hiddenness, the sense of something waiting to be found, is perhaps most evident in a number of works from this period that present the facades of houses or shops. These are not so much pictures of buildings as portraits of them; even in the blankest exterior there is a breathing, palpable, sense of interior life, of something intimate and unknowable occurring. While some of these are paintings, more are paper collages, typically encased in the deep frames used by butterfly collectors to display their catches. These cases seem to be, like the walled garden, another kind of self-contained space. Dolls and doll houses will become a recurring theme, and, these façades seem already to hover in some indeterminate, uncomfortable, interchangeable space between humanity and doll-hood. Like much of her work, they could easily be sentimental, but they aren’t. But then, you couldn’t call them unsentimental either. Instead, they are powerfully disinterested in what you think of them – another aspect of that determined sense of interiority again, perhaps. She needed determination: in the spring of 1948, her cancer returned; in the early summer of 1950 a secondary cancer was diagnosed in her spine; she moved into a nursing home shortly after.

A year to the month after Garwood painted Hide and Seek she was at work on a painting titled Mrs Noah’s Picnic. ‘Tirzah, quite triumphant, is painting Mrs Noah and the engine Nero under the wonderful driven sky,’ Garwood’s second husband, Henry Swanzy, whom she had married in 1946, wrote on 24 March 1951. Nero was one of two toy trains whose departures and arrivals she painted repeatedly in her last years. Mrs Noah is a doll looking implacably out of the picture; one doll-child has her back turned to us, another is reaching for Mrs Noah’s hand. Garwood left the painting unfinished: she died three days later. The picnic blanket remains a blank space on the canvas, the crockery lightly sketched. It’s a small pocket of incompleteness in an exhibition which gives back to the world Garwood’s otherwise complete vision of life across two decades of work in multiple media.

Looking at her later work, in particular, you might at first glance think some of it to be childlike: the dolls, the toy trains, the low angles, the naively distorted perspectives, and so on. But it’s truer to say that Garwood is thinking with the things of childhood, which is something else entirely. Consider Doll’s House Room, a painting from 1950, which shows a bedroom from Garwood’s own childhood doll’s house – by then in possession of her nine-year-old daughter Anne. A doll of Garwood herself, presumably as cancer-ridden as Garwood was by then, sits helplessly upright in bed, disconcertingly echoing The Wife, seen earlier in the exhibition. Across the room a doll of Swanzy is no less helplessly unbalanced as his rocking chair rocks perilously backwards to the very point of tipping over. In other hands it might be mawkish or twee; here, I think, the complex layers of association in the image – imagination and incapacity, childhood and mortality, love and its ultimate insufficiency, and so on – together with its tonal mix of resignation, horror, humour, and dread, make for something enduringly strange and moving.

More generally, in Garwood’s handling, the dolls and other static figures – there are snow-women, toy soldiers, the clay stopper from a Victorian water bottle in the shape of a Spanish lady, and so on – appear not so much objects as forms of enchanted matter. They, too, seem to have unrevealed inner lives dramatised in scenarios that are likewise at once apparent and opaque. You want to say that these works are dreamlike, but I’m not sure that they are. Dreams are fleeting, after all; this is all more durable than that, more timeless. At least, these paintings play with time in much the same way as Garwood plays with scale. A dragonfly fluttering above a tortoise and a frog in a loosely primeval landscape painting titled Prehistoric Encounter seems contemporary with Springtime of Flight, in which a large yellow butterfly and a Bristol Boxkite flit over a bank of tulips and daffodils. The delicate, rickety elegance of the biplane seems at one with that of the insect life and the ancient structures and forms of leaves and plants and grasses that recur.

That sense of timelessness belongs, I think, to the ineradicable magic of folk myth and fable. And thinking along those lines brought me to a revelation that what unites Garwood’s figurative work here (a handful of portraits aside, perhaps) is the sense of narrative. The fact that in the late works you increasingly have no sense at all of what the story might be makes them, paradoxically, yet more compelling. Driven by the intense, liberating clarity of terminally illness, Garwood offers us disorienting, transitional scenes of inscrutable mystery and wonder: life itself, never still, hiding in plain sight. The more you look, the more astonishing it all is.

I found myself thinking of a quote from Middlemarch. ‘If we had a keen vision and feeling of all ordinary human life’, George Eliot wrote, ‘it would be like hearing the grass grow and the squirrel’s heart beat, and we should die of that roar which lies on the other side of silence.’ You can hear the grass grow in the visionary glow of these last paintings in this last year. It was, she said, the happiest year of her life.

Tirzah quite triumphant. So she is.

Tirzah Garwood: Beyond Ravilious is at Dulwich Picture Gallery, London, until 26 May 2025.