Seven floors high, over 250 metres long, eight entrances – a great hulk of grey, weathered concrete slabs built in the early 1960s at Stefan cel Mare. "We call them matchbox flats," says Mircea Cartarescu and holds open the door of the lift, which is just big enough for him, his wife (the poet and journalist Ioana Nicolaie) and myself to squeeze in. On the fifth floor his parents open the door, and he leads the way into his childhood bedroom. The room is furnished with a large bed, a cupboard, a table and a chair.

I have never been here before and yet I know the room. It is where Cartarescu's novel "Die Wissenden" (or "the knowing" - vol.1 of the "Orbitor" trilogy) begins: the young narrator sits on the bed and looks out over Bucharest just like Victor Hugo's chimaera looked out over Paris. Cartarescu walks into the space between the bed and the window and looks out: "When the prefab block opposite was built I lost my view of the city." He turns to us and says happily: "Here everything is still as it was." Everything is like it is in "Die Wissenden".

"Joyce got Dublin," complains Mircea Cartarescu in his essay "My Bucharest," "Borges had BuenosAires, Durrell had Alexandria" And what did he get? Bucharest, "nameless boredom", "ugly and provincial". But then Cartarescu discovered another Bucharest. His trilogy "Orbitor" (meaning glaring, orginally published in 1996, 2002 and 2007 - extract in English) describes a city awash with thrills and nightmares. Cartarescu captures the socialist capital – where his parents met and he grew up – in the moment of its downfall. His magical realism gives a prefab block – in reality a celebration of the perpendicular – an oval window and the socialist years a metaphysical superstructure. Bucharest becomes a mystical city.

In the old days the door to the roof was never locked, but now it is. The key is kept by a neighbour, a lanky caretaker who greets Cartarescu without a hint of surprise. The author – casually dressed in jeans and a striped T-shirt – often brings strangers to his parents' home. Cartarescu, who has been a lecturer in Romanian literature at Bucharest University since 1990, smiles and tells how one of his students photographed everything here, even his parents, and submitted the photographs as a dissertation.

His face is generally earnest – with dark eyes framed by long, falling locks – but a smile flits across it as we climb the stairs. On older photos he looks like Jim Morrison, but these days his excesses are of the metaphysical kind. Cartarescu, an authority on Romanticism, is a melancholy seeker of childhood. On the roof here Cartarescu once played with the neighbours' children. At the end of the long block there is a dark lightwell. Cartarescu peers down into it and seems to shiver in the midday heat. When they were building the block he and his friends would climb into the builders' carrier and pull themselves up to the giddy heights of the roof hand over hand. "In the third volume my main character falls out while playing this game and Hermann saves him."

Hermann is an angel-like figure, like those that also appear in Cartarescu's collection of short stories "Nostalgia" (1989, uncensored 1993, German 1996 and English 2005). He already appears in "Die Wissenden". "The left wing" is its Romanian subtitle, "the body" is the subtitle of the second volume and "the right wing" the third. "Sometimes I explain my book as a mystical butterfly or a flying cathedral," says Cartarescu. The last volume, which appeared three months ago in Romania and has already sold 20,000 copies, brings the Apocalypse.

We are "larvae of an astral being", the novel says. The larvae's metamorphosis is triggered by the memory, an inventing memory. The remembering and therefore transforming hero asks the same question as Oedipus: "Who am I?" Only rather than his father, he is searching for his mother, finding her finally in the street where he spent his early years. The alley has been renamed "Pancota", which is similar to the Romanian word for the female lap. The narrator enters the alley, finds his childhood home and opens the door. Lying on the bed in dazzling light is his mother, naked in the beauty of her youth with the butterfly-shaped birthmark on her hip. She "welcomed me with a smile".

As we stroll along the endless roof, Cartarescu tells me about butterflies and spiders. In "Orbitor" they stand for two different worlds. "If I hadn't become an author I would have been an entomologist. I used to collect butterflies and I still look for spiders when I'm out walking." As well as insects, he is also keen on neurophysiology and quantum physics. That explains many of the fine foreign words that are so prominent in his books. Even the power station chimneys seen from the roof are "paraboloid conduits". Lyrical Byzantinism? Perhaps. But also a manneristic magic wand with which Cartarescu transforms the world, inventing miracles and monsters. Maybe he simply made up some of the words? Cartarescu shakes his head: "Very few. After all, it's about the ineffable."

In 1980 Cartarescu's writing focussed on the everyday. At the age of 24 he joined the legendary university "Monday circle" led by literary critic Nicolae Manolescu. "Faruri, vitrine, fotografii" (headlights, window displays, photographs) is the title of his debut work published that same year. "We moved from the European poetry tradition to the American, we wanted to be faster, harder, more powerful." Allen Ginsberg, John Ashbery and Frank O'Hara were the models for the "Eighties Generation", who dedicated themselves to the reality of here and now and survived unscathed at the university despite their dissident views. After producing three volumes of poetry as a student and while working as a primary school teacher on the outskirts of Bucharest, Cartarescu began writing prose. The narrative round dance entitled "Visul" (the dream) appeared in 1989, two months before the revolution. The original title, "Nostalgia" was ruled out because of the Tarkovsky film of the same name, the first story cut out by censors who judged it to be too violent, and Elena had to be renamed Maria to avoid any possible association with Elena Ceausescu.

After the revolution "Nostalgia" could appear uncensored and Cartarescu could finally become a university lecturer and travel. As we leave the roof, passing some scrawny plants, he tells of the initial shock felt by Romanians, who were used to shortages of everything, on first entering the West. In the meantime Cartarescu has got used to the West: "Since 1990 I've spent half my life abroad."

For the lads even the hundred metres between Entrance A and Entrance E were an adventure, and the narrow passage between the block itself and the building glowering in the shadows of its courtyard was a real test of courage. Behind it, just in front of the creepy lightwell, there is a little open space. A stairway leads up over a ditch with cellar windows to the building itself, but it is useless, there is no door. Cartarescu points to the puzzling platform: "The throne of our childhood games. When we jumped into the ditch we could hear the screams of prisoners being interrogated, through the windows. Everyone knew that the building was a secret police post." He looks around again. The courtyard is eerie. But it is still there. Every time Cartarescu revisits the places of his childhood something more has been torn down.

Children's games within earshot of torture fit the Manichaeism and the longing to overcome it that are themes running through Cartarescu's work. The dead come to life, stone turns to flesh, a man into a woman. The realistic course of events glides off into mystical realms. At the end of "Nostalgia" a self-taught organist playing music of the spheres creates a new Milky Way. The trilogy "Orbitor" is also cosmological. But Cartarescu would not be a dialectically-minded author had he not written quite different books during the same period: "Levantul" (levant), a parody of Romanian literature in the style of the nineteenth century, the short "Travesti" about a sex change, a children's encyclopaedia of dragons, and a collection of short stories, "De ce iubim femeile" ("Why We Love Women"), commissioned by the Romanian Elle magazine.

In his flat a day earlier, Cartarescu had proudly told me how "Why We Love Women" had become a bestseller, selling 140,000 copies so far. "It put me at number one on the bestseller list for a year, ahead of Paulo Coelho. I don't regret a word." Nonetheless, the "visionary" of "Orbitor" is closer to his heart. The trilogy arose "like a great poem". "I wrote as if in a trance, without a plan or preliminary studies. Nobody believes me, but wait, I'll fetch the manuscript." The eight or nine A5 notebooks are covered in blue handwriting, almost without corrections. "I knew I wouldn't fail, whether it took ten years or thirty." From the bookcase in his study a small drawing of Jesus in a crown of thorns looks on. "I grew up an atheist, my parents were communists. And I don't hold with the Church as an institution. But after the revolution I bought a Bible and read in it every day. It has brought out a mystical, transcendent side in me and changed my writing."

As the author of a voluminous study of Romanian postmodernism, Cartarescu strives to overcome immanence. He says that it is only his narrative style – for which he thanks Thomas Pynchon – that is postmodernist, not his impetus. And anyway, he says, the age of postmodernism ended with the attacks of September 11. Phantasmagoria are also at home in the reality of Bucharest. If Cartarescu stands on tiptoe on the flat's second balcony he can catch a glimpse – beyond the roof opposite – of the gaudiness of Ceausescu's Neuschwanstein, the vast People's Palace, like a lump of frozen yellow foam.

They are building everywhere in Bucharest. Behind the prefab of his childhood a new block of flats has been squeezed in. Mircea Cartarescu and his wife would like to have bought a flat there but they were too expensive. As a lecturer he earns 300 euros a month, and does not expect to be a appointed professor for two or three years. So for years he has been writing a weekly political essay for a major daily newspaper. When Cartarescu speaks about parallels with communist structures or business magnates buying up political parties and the media, he looks grim. The bread-and-butter writing is important to him, but it keeps him from literary work. He has scholarships abroad to thank for "ninety percent" of his books; the third volume of "Orbitor" was written at Schloss Solitude near Stuttgart. Mircea Cartarescu, Ioana Nicolaie and their four-year-old son Gabriel only returned from there six months ago and have not yet really settled in properly at home. They remember Vienna with particular longing. Flats there are no more expensive than in Bucharest, and the city of his childhood is safe now.

*

Jörg Plath is a journalist and literary critic based in Berlin.

The original article was published in German in the Neue Zürcher Zeitung on November 3, 2007

Translation: Meredith Dale