When Michel Faber began writing his latest novel, The Book of Strange New Things, he knew it would be his last. What he didn’t know is that it would end up being not just a farewell to his career as a novelist, but also to his other half, Eva Youren (in their case, the term ‘other half’ is practically literal). Faber’s wife – his unofficial manager / literary editor / mentor / PA / friend, or to give her a more grandiose label, his personal saviour (the reclusive Faber once thanked her for ‘bringing me back to earth’) – was diagnosed with a rare plasma cell cancer, and sadly died in early July.

‘The book was conceived before Eva was diagnosed,’ says Faber who, when we meet in the living room of his Edinburgh flat, is wearing several days’ stubble and a threadbare Rammstein t-shirt. The chameleonic, addictive fiction writer is probably best known for his Victorian sex-work epic The Crimson Petal and the White, and alien sci-fi thriller, Under the Skin which was recently adapted into a film with Scarlett Johansson.

He may be a little subdued today, but Faber hasn’t lost any of his ability to casually drill deep into the conversation, mining it unexpectedly, hitting hard insights while talking about his cats, or a pair of shoes. He’s just back from an American book tour, and pulls out Eva’s red ankle boots from his not-yet-unpacked bag. He beams sheepishly as he explains how he photographed the shoes next to things Eva would have liked.

‘The book was always going to be about grief; grief at how we treat each other and the planet. Loss of precious human beings. But I wasn’t expecting to lose Eva.’ Faber always intended his final novel to be ‘a journey into the darkness’, relying on the reader’s trust as he led them, and himself, into unmapped territory. An ‘obsessive shaper’, his work this time was deliberately much less planned. ‘Always being in control of everything, I felt uneasy. Really good books need a chaos element, something weird or inexplicable.’

With supremely cruel irony, Faber has noticed before that his books sometimes end up being ‘anticipatory, almost prophetic’, and The Book of Strange New Things – about a Christian missionary’s voyage to another planet – was no different. In this part dystopian travelogue, part epistolary love story, Peter and Bea are separated while he goes to preach to the indigenous people of Oasis; a foetus-faced species who speak with otherworldly, asthmatic voices, sounding like ‘a field of rain-sodden lettuces being cleared by a machete’.

As Peter makes progress with the Oasan people, Bea is back on earth, witnessing it short circuit in freak weather disasters and spasms of civil unrest. ‘It’s an enormously sad book, obviously. Heartbreaking things happen in it. I was writing it, line by line, as Eva became incredibly ill, and later when I lived with her in the hospital where she died. But I didn’t think it would be fair to make it the ultimate feel-bad book. I couldn’t do that to people.’

Faber wanted to find some consolation, without straying into cheesy, sentimental territory. ‘So often the “uplifting” thing just ends up being really platitudinous. Pathetic and specious. I really wanted to avoid that.’ And he has. On the surface, The Book of Strange New Things reads like an Orwellian bad dream, if JG Ballard and Kurt Vonnegut found themselves wandering the sterile hallways of a space base filled with piped-in Patsy Cline songs, maggot-based hybrid foods and out-of-date lesbian porn mags. It’s a morose, matter-of-fact allegory on modern life, but one enlightened by Faber’s gentle, resigned wisdom.

‘I’m not normally superstitious,’ says Faber, ‘but I didn’t write any dedication in the front of the advance proofs. All the other books were dedicated to Eva, but for this one I was a bit spooked. I was very much hoping for a remission, that she’d live longer; it felt almost like inviting bad karma.’ The finished copies, to be published three months after her death, will say, ‘For Eva, always’.

‘Eva said she’d like a dedication. This one was very precious to her. She’d worked on it a great deal, as with all the others. It’s obviously valedictory, and about saying goodbye to the flesh.’ As the person who initially jumpstarted Faber’s career and coaxed him out of his crippling shyness, Eva was ‘distraught’ at the prospect of him giving up writing fiction. ‘She was worried about me just shutting myself away as I tend to do. But I’m trying to say yes rather than no, and I want to live the sort of life she’d have liked me to live after her death.’

Although Faber says he’s written his last novel (‘Most books and works of art disappear down the plughole. If one of my books is destined to be remembered by anyone, it’s probably already out there’), he’ll continue writing poetry and non-fiction, with plans for a book on music theory ‘which will probably appeal to 178 people in the whole world’. He also talks of an intriguing plan to possibly ‘collaborate’ with Eva, and add to some of her own unfinished writing. ‘We discussed that. We had some wonderfully precious and intimate times and the relationship definitely deepened towards the end. It’s hard to think that might be extinguished.’

The Book of Strange New Things is published by Canongate, Thu 23 Oct.