“A culture of lying, the outrageous failures of our political system, Westminster being so corrupt, so chaotic ... ” Max Porter is talking about public life in the UK today, about which he finds almost everything “revolting”. Porter’s debut, Grief Is the Thing With Feathers, a novella-cum-prose poem about a bereaved dad bringing up two boys, based on the death of his father when he was six, was one of the stand-out books of 2015. He was hailed as “a writer bursting with originality”, but he was reluctant to write a second novel without feeling the same sense of urgency. Now, four years later, this despair at the state of the nation, combined with his “obsessive” fears for the environment, has sent him back to his desk for Lanny, an inventive take on the “missing child” narrative and a meditation on Englishness, made strange by the otherworldliness that distinguished his earlier novel.

Porter didn’t want “just to write angry stuff about tabloid poisoning”, a straightforward anti-Brexit or eco-crisis novel. “This isn’t stuff I want to write about explicitly.” Instead, he hoped “to have a kind of philosophical reckoning” with all these issues. “The question was ‘How do I write about England?’”

His first attempts were “rather unhealthy, because various political feelings collapsed into the effort. It was not a nice place I was writing about”; and, despite all these anxieties, he longed “to write about how strange life is, and beautiful”. Indeed, such gloominess seems at odds with the ebullient novelist (not yet 40), who shrugs off his parka and begins talking with infectious passion about everything from poetry (“I’m never not thinking about Emily Dickinson”) to his worship of trees. He insists that he is not the whimsical, nature-loving Lanny at the heart of his new novel – “I’m a bit more worldly than that” – but his boyish enthusiasm does bring a blast of energy into the hush of Faber’s Bloomsbury offices. Starting out in a bookshop (he won the Bookseller of the Year award in 2009), he was, until recently, editorial director at Granta, where he looked after writers including Han Kang, Eleanor Catton and Rebecca Solnit. “Editing is wonderful, but you are soulmate, analyst, bloody torturer, exploiter all rolled into one,” he says. He wrote Lanny on his Fridays at home, by which time he was desperate not to have “other people’s words in [my] head”.

Porter has found his own voice, combining the domestic and the mythic, the realist and the poetic, and Lanny is as playfully polyphonic and experimental as his first novel, made clear by the spidery italics crawling off the page. The omniscient, fable-like figure of Dead Papa Toothwort, “a sort of voyeur” who roams below the earth and eavesdrops on the villagers, fulfils a similar function to the cranky Ted Hughes-inspired Crow in Grief Is the Thing With Feathers. “Is he a metaphor? Is he real or not real?” Porter intended this novel to be even more ambiguous. And it was only once he had Dead Papa Toothwort, he says, that it really came together: “All second novel syndrome just disappeared. I remember shouting to my wife: ‘I love this. I want to do this for the rest of my life.’”

Cillian Murphy in Grief Is the Thing With Feathers by Max Porter, adapted and directed by Enda Walsh. Photograph: Colm Hogan

In some ways Lanny was “an escape” from the acutely personal material of Grief Is the Thing With Feathers. He describes his first novel as almost “accidental”, its success completely unexpected; he certainly wasn’t prepared for seeing his childhood recreated on stage in Enda Walsh’s adaptation starring Cillian Murphy, which he went to see with his brother last year. “There’s me going: ‘No, it’s not autobiographical,’ and then sobbing because there’s my bunk bed. Extraordinary,” he laughs now.

He worried that people would assume Lanny was also autobiographical, given that, like the characters in the book, Porter and his family have recently moved out of London to just outside Bath; but no, the novel predates the move, although “a number of relatively odd echoes occurred”. Robert (a City banker) and Jolie (an actor-turned-gruesome-thriller writer) and their charming but troublesome son Lanny are new arrivals in the unnamed commuter village.

The novel was finished while travelling up to London: “It was like having Bekonscot model village in my head with me while I’m going about my day.” He would imagine seeing characters such as Robert on station platforms. With his Apple Watch and porn habit, Robert is Porter’s attempt to “write honestly about men these days” in a way, he feels, is rarely found in modern fiction, where he would typically be “more of a hero, or more flawed. Usually when you get a character like Robert he’s killing people. I wanted him to be likable and understandable. He’s just a completely straight-up bloke and therefore he has to fail.”

Bekonscot Model Village, Buckinghamshire. Photograph: Alamy Stock Photo

Jolie befriends Peter Blythe, known locally as “mad Pete”, a controversial artist once famous for his explicit erotic work, and asks him to give Lanny art lessons. Then Lanny goes missing. The germ of the novel goes back nearly a decade to a poem Porter wrote when he was working as a bookseller and still trying to find his form. Beginning with the line “There’s a tree up there where this thing happened”, it was about a friendship between an old man and a boy, written around the time of Operation Yewtree, in response to “this sense that children couldn’t be left in the company of adults, and who could we trust”. But he was also reacting against an atmosphere of hysteria and assumption, and in the relationship between Lanny and Pete he wanted to explore ideas of creativity and innocence, to show the huge influence “special inexplicable friendships” can have on young people, based on his own with his godfather, who loved making things, or his next-door neighbour Pam, a prison art teacher, who gave him drawing lessons as a boy.

What makes Lanny more than another twist on the missing-child genre of so much crime fiction as well as TV shows such as The Missing and Broadchurch? Porter says he didn’t see those dramas, but was keenly aware of a crossover with Jon McGregor’s acclaimed 2017 novel Reservoir 13, which also subverts expectations by focusing not on solving the mystery of a young girl’s disappearance but its impact on the Peak District village where it happened. “I thought: ‘Oh no, I can’t write that any more’,” but he was relieved to find it was “not remotely similar”. However he agrees they both address the same question: “From a literary point of view, now we’ve had all these books that fixate on missing children or dead children, or brutalised women or serial killers, all this stuff that people love to read – what do you do afterwards?” His answer was “to take out all the bumf of the realist novel – what does the policeman look like, do you see so-and-so drinking his coffee – and just have the comments that seem to really shine a light on a community left in”.

The result is a cacophony of voices, what Porter calls a “soundscape”, of snatched conversations from the village. “I love everyday language,” he says. “I love slang, I love children’s language, I love hip-hop, I love the proper use of language. If you are a lover of language there is no hierarchy between low and high or anything like that.” He plundered “all sorts of brilliant books” for the random phrases that Dead Papa Toothwort overhears from his subterranean hiding place – “fresh out of Silk Cut”; “what next, Polish adverts in the parish mag”; “Dave has bucket-loads of dahlias”. The visual effect is a sort of root-like concrete poetry tangled between the main narrative, a device he painstakingly worked on with a production editor at Faber. “It’s not bound by the printed conventions of the book. It’s coming from somewhere else.”

A page from Lanny Photograph: Faber

The novel makes great play with poetic or theatrical borrowings – little crosses scattered throughout the text, for example, “are breaths, like a dash in Dickinson, or a silence on the stage”. (All, according to literary prejudice, either inspired eclecticism or infuriatingly tricksy.) He describes himself as “a compulsive maker of not very good things: collages, little boxes, with toys and bits of cut out paper.” The novel began as drawings on his wall, and he will always draw before he writes, sketching scenes if he gets stuck. “Some people like to walk, or go birdwatching. I like to sit and draw,” he says, showing me a pretty line-drawing he doodled across the novel’s title page on the train this morning. “The idea that I would only ever have a laptop screen and have to write straight on to it is intimidating for me because it happens elsewhere.”

His childhood home in High Wycombe was always very creative: “Everyone would have a sketchbook in their bag on holiday.” His mother is a photographer and his Welsh father, who didn’t live with them, was “arty in sensibility, but never really got his act together”. His brother is now “a radical ambient drone musician” and carpenter. Porter studied history of art at the Courtauld Institute in London, followed by an MA in radical performance art, psychoanalysis and feminism.

While he knows he may have to return to publishing or try teaching at some point, for “this little moment” he is enjoying being at home “thinking about literature, playing games, drawing” and finds “the chatter” of his three boys, aged nine, seven and three, an inspiration: “It’s a bit of school run, a bit of cooking, then it’s football – that’s where I’m getting the energy from.” He often works alongside his wife, his “childhood sweetheart”, now a freelance proofreader: “We sit next to each other and we break for coffee. It’s lovely.”

He chafes against what he sees as a risk-averse tendency in realist contemporary British fiction. “We have a lot of very good, very polished beginnings, middles and ends, and we have lovely novels about people like us. But what there hasn’t been enough of for me is what I found in the books I fell in love with when I was younger, by people like Russell Hoban, where you have movements between worlds, the possibilities of genre fiction.” For him, Alan Garner is “probably the most important postwar British writer” for both children and adults. And although he believes Britain is going through “a kind of golden age” not only in fiction, but in poetry and music – “I think in times of political uncertainty the culture flourishes” – he admires what he sees as the greater ambition of American literary fiction and is a big fan of George Saunders, Ben Lerner and the poet Ocean Vuong.

His next novel will be about intimacy, “a relationship that has a very complex spiritual element to it”. After wrestling with Brexit Britain, he has “turned into a right old history nerd” and is reading about saints and paganism. He is working up to something like a personal manifesto for fiction: “I don’t think it is impossible to have books that are difficult or confront quite dark things or are uncomfortably honest about sexuality or whatever it is, while at the same time being fundamentally kindhearted or celebratory about the human condition.”

• Lanny is published by Faber (£12.99). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99. Max Porter leads a dramatic live reading at Southbank Centre on Thursday 28 February.