NEW YORK, NY.- In 2008, at the age of 21, Katherine Rundell aced perhaps the most fiendish test in all of British academia: the entrance exam for All Souls College at Oxford University. For the final portion, a three-hour essay on a single word, “novelty,” Rundell managed to weave in references to both Derridean deconstructionism and Christmas crackers.

Dazzling the examiners with her erudition, Rundell was made All Souls’ youngest woman scholar ever, and given seven years to pursue a doctorate on John Donne’s poetry and the genealogy of style, tracing its impact on other poets. And so it was a cause of some befuddlement in the ancient halls of the college when Rundell announced to her adviser, Colin Burrow, that she also wanted to write children’s books.

“I knew that writing fiction for children is a serious and good thing to do,” recalled Burrow, a scholar of Renaissance literature who happens to be the son of the great English fantasy writer Diana Wynne Jones, author of the young adult novel “Howl’s Moving Castle,” among other things. “Politely, that was not a view shared by all of my colleagues.”

But Rundell forged ahead. In the 16 years since, she’s produced more than a dozen works — children’s books, a play and several books for adults — picking up a dizzying constellation of awards along the way. In 2022, she published “Super-Infinite: The Transformations of John Donne,” a general-audience spinoff of her thesis which makes a witty, erudite, joyful case for the continued relevance of Donne’s poetry; it won the 50,000-pound (or $66,000) Baillie Gifford prize for nonfiction.

The following year, she published “Impossible Creatures,” a fantasy novel for children, in Britain. An instant bestseller, it was named Book of the Year by the country’s largest bookstore chain, Waterstones; Rundell was named author of the year at the British Book Awards. Reviewers compared her to J.R.R. Tolkien, C.S. Lewis and Philip Pullman.

“This is as close to perfect as fiction gets,” Bea Carvalho, Waterstones’ head of books, said.

“Impossible Creatures” is the story of a boy who travels to an enchanted archipelago populated by mythical creatures, teams up with a girl who can fly and embarks on a perilous mission to rescue the magic that holds the world together. It was published in the U.S. this month, with a first printing of 300,000 copies.

Its arrival provides an opportunity to meet not just a bestiary of fantastical animals — tiny irritated dragons, scholarly sphinxes with the ancient right to eat visitors who can’t answer their riddles, gossipy squirrel-like creatures called ratatoskas — but also its author. She’s a bit of an impossible creature herself.

Rundell has an air of perpetual delight, a thesaurus-level vocabulary, a deep passion for the natural world and a reputation for gentle eccentricity. In college, she liked to relax by walking on a tightrope strung up in her room. (“It’s such an unhelpful talent,” she said.) Her second children’s book, “Rooftoppers,” reflects one of her other occasional pastimes, clambering across the rooftops of buildings.

The children in her books are often orphaned or alone, confronting life-or-death situations but having thrilling adventures while doing it.

“Fiction is such a brilliant way of talking to children about huge ideas — about politics and power and corruption and care and action,” Rundell, 37, said over lunch in London early in the summer. “But it’s really bad manners to offer a child a story and give them just a moral.”

She ordered herbal tea, having become allergic to caffeine after a period some years ago in which she regularly got up at 4 a.m. and wrote for five coffee-fueled hours before reporting to her job teaching Shakespeare to Oxford undergraduates. Coffee now makes her shake uncontrollably. “The best case is amorphous dread,” she said cheerfully. “In the worst-case scenario, I vomit and pass out.”

Rundell was born in Britain, but spent much of her childhood roaming outdoors with her brother and their two foster sisters in Harare, Zimbabwe, where the family moved when her father got a diplomatic posting there.

“We lived in places where you could wake to wildness,” encountering “monkeys and snakes and various kinds of incredible birds,” she said. “If you went further you could meet kudu and wildebeest, and zebras, impalas and other plains animals.”

Her mother, a lecturer in French, encouraged an interest in poetry by printing and cutting out poems, including “some of the less scurrilous and funnier works by John Donne,” Rundell said, and affixing them to the bathroom wall so that the children could gaze upon them while brushing their teeth.

“They paid us to memorize the poems,” Rundell said of her parents. “I was a very mercenary kid and had quite a retentive memory.”

Her books are infused with loss, something she encountered early on. When she was 10, her beloved sister Alison died from a congenital illness at the age of 16.

“I’m wary of talking about her too much in public, because what can happen is that one of the great loves and great losses of your life will seem like a public performance of grief, and I somewhat want to keep her mine,” she said. “She was the most gentle person I’ve ever met, and so when we lost her, I just knew I would never meet anyone like her again, and I never have.”

Then, when Rundell was 14, the family moved to Belgium, a place she found dismayingly prosaic.

“Belgium itself did nothing to harm me except not being Zimbabwe,” she said, but alert readers will find tiny jokes about Belgium tucked inside her stories.

She did her undergraduate work at St. Catherine’s College, Oxford, and in 2008 wrote her first children’s book, “The Girl Savage,” about a child wrested from Zimbabwe and dispatched to an English boarding school. Through a friend, she sent the manuscript to Claire Wilson, an assistant at Rogers, Coleridge & White, who became her agent.

“I can still vividly remember sitting at my desk and reading it,” Wilson recalled. “It felt completely unlike anything else I had ever read, like a lungful of fresh air.”

The book was published in Britain in 2011; three years later, it appeared in the U.S. as “Cartwheeling in Thunderstorms,” winning the Boston Globe-Horn Book Award for Fiction.

Then came Donne. Rundell never expected to write a general-interest biography, she said, but as she worked on her graduate thesis, she became increasingly enamored of the poet at its center, as well as of the sublime work he produced under punishing conditions — religious persecution, penury, chronic illness, thwarted romantic longing. Her book is both labor of love and one-woman public relations campaign. “What I really wanted was a Trojan horse to make people read his poetry,” she said.

She went on: “John Donne is so bound up with disaster and chaos and dread, but also with this sense of mankind as a staggering thing. He imagines each person on the planet as infinitely larger than the planet itself.”

Rundell lives in a tiny flat in north London, near her longtime partner, film and literary agent Charles Collier, and his 12-year-old daughter. She’s reached a point of financial equilibrium, she said. “I don’t make enough to be rich, but I make enough not to worry, and that has made a world of difference,” she said.

When she won the Baillie Gifford prize, she gave the money away to climate and refugee charities. “It was such a shock to win, but it wasn’t a debate, internally, as to what I would do with the money,” she said.

Her next book, “Vanishing Treasures: A Bestiary of Extraordinary Endangered Creatures,” is for adults and consists of loving, playful essays about animals that are endangered or hold a subspecies that is endangered: sea horses, lemurs, golden moles and more. It’s pervaded with both wonder and worry, as indeed is much of her work.

“The unifying thread is that our world, as chaotic and burning as it is, demands our astonishment because of its beauty, its generosity and its intricate variety,” Rundell said. “It’s so colossal that to not salute it would be a failure of imagination, perception and intelligence.”

She continued: “And so I want these books to say, ‘Pay attention. You owe the world your attention. You owe the world your love.’”

This article originally appeared in The New York Times.