IN my head, Kate Tempest is the superhero. Her alter ego Kate Calvert is the one who wears glasses and pretends to be clumsy. And Tempest, well, she is the rapping, poetry-slamming, Mercury award-nominated, Ted Hughes award-winning, probably cloak-wearing wordsmith leaping over tall rhyme schemes with a single simile.

But it’s possible that I may be projecting. Ask her the difference between Kates Calvert (birth name) and Tempest (performance name), and the woman who is both Tempest and Calvert can’t see much. “Kate Calvert doesn’t talk to interviewers on the phone or stand up in front of loads of people she doesn’t know. Kate Tempest is a public figure and Kate Calvert is who I am to my friends and family.”

That’s it? You don’t become a different person when you become Kate Tempest? There are no super word-powers involved? “Not any more than anyone else does when they go to work. When you’re not hanging out with your friends and family you’re a different person. But it’s not more you or less you. It’s just you in public.”

It’s Wednesday, 9.30am, and Kate Tempest, 30, is walking her dog Murphy, a Husky Malamute cross. Think “massive wolf”, she says. “It’s a cold spring morning and I’m very happy,” she tells me.

That’s partly to do with the fact she has a new novel coming out. Her first, a fact she finds both “exciting” and “pretty terrifying”.

“Having got to the end of the process I’m now ready to write a novel. Do you know what I mean? You get to the end of all this agony and work and difficulty and elation and suddenly you realise what it takes to write a novel and you wish you could go back and start again.”

The one she has written, The Bricks That Built The Houses, will do for the moment. It’s a novel about youth and drugs and desire and dancers. It’s a book about south London and, as you might expect from a poet and rapper in love with language, one that now and again overindulges that love yet rings new notes out of letters and words.

It’s also about the changing face of the capital city. About gentrification and its costs. Near the book’s beginning Harry, a female drug dealer, is sitting thinking about the city she lives in. “It makes Harry sick to her stomach, the way London’s changing. And not just this side of the river, either. It’s changing down south. She hardly recognises it these days. It’s heartbreaking.”

Tempest’s own view is a little more nuanced. “Yeah, it troubles me. It troubles everybody who’s grown up here. But I suppose big cities are built on movement, aren’t they? It’s all very well me complaining about the changes that are happening. But at the same time I think all borders should be open. People should be moving. I welcome the idea that places shouldn’t belong so inherently that people can’t come in and be welcomed. So how can I say that on the one hand, for example, about what’s happening in Calais and on the other hand ‘f*** all these yuppies moving into south London’? I can’t balance those two things.

“OK, the centre of the city is moving out and the city has always been about commerce. And it’s kind of disgusting because I never had that experience of it growing up there. When I was growing up, south London was outskirts. South London is central now.”

She pauses. “It’s a difficult thing to wrap up in a soundbite,” she says. “It’s taken me a whole novel to try and get my head around it.”

Tempest was not long into her teens when she started getting up on stage and rapping. It’s hard from a distance to picture the girl she was, a little 16-year-old refugee from a Harry Potter novel, all glasses and duffle coat. The girl who struggled at school and, as she has said in the past, suffered from homophobic bullying. The girl who then got up on stage and commanded it. But maybe here’s where we can reframe her in the superhero mode. After all, she admits, the idea of being a rapper was so magical that it gave her the self-belief to get up on stage in the first place.

“The confidence you can acquire through carrying around in your brain and in your mouth this secret weapon of lyrics; the way that allows a rapper to move around the space – that was magic and intoxicating. I found the whole thing electrifying. Watching MCs and after a few years becoming one. It was amazing.”

Tempest has told her origin story so many times, she’s not sure if she can really connect with the feelings she had then. “It feels so much part of me that I don’t have any context to compare it to. I didn’t have any other way other than, ‘This is my compulsion and I want to be up there doing that’.”

Well, did being “up there” alter her sense of self? “Yes and no. I was no more understood in the circles I moved into than in the circles I moved out of. I’ve always been a strange figure for people to compute initially. But then through having this thing of lyrics and language and music it gives you this contact point and that’s been at the bedrock of my existence. I feel so lucky and blessed to have this point of contact with other people, the community I discovered in south London of musicians and players and writers and artists. More than a superpower it’s very real and rooted in real experience.”

Creativity threw her a lifeline, and now she's suspicious of people who don’t grab hold of their own. “I meet people and they feel that they haven’t quite managed to dedicate themselves to their artistic path and they have all these regrets and I just can’t imagine … I literally can’t imagine not throwing everything at my work and I feel like if it’s possible for you to not do this then you shouldn’t be doing it. If that’s even a possibility then this isn’t for you. That’s an easy thing to say from this position, I suppose, but that’s how I feel.”

In a sense, Scotland can make a small claim of ownership of Tempest the poet. Don Paterson spotted her performing and became a mentor. He has been hugely influential on her poetic development. “He’s an incredible man and I couldn’t begin to explain how profound an effect it was to sit down with him and read my poems and know that someone was reading them that closely and that carefully and was putting that rigorous attention onto each word. Suddenly knowing he was even going to see a poem made me write it in a totally different way.”

There’s a new book of poems in construction as we speak. A new album scheduled for September. But for now,Tempest has a novel to promote, that seems obsessed with pub life. Is that possibly drawn from life? “Yeah, I’ve spent a lot of time in pubs over the years. My local pub where I spent a lot of time when I was meant to be writing is a place where I feel very connected to home, to south London, because it doesn’t change. It’s the last one there. It’s the same faces. I see people I’ve known from school. And before that.

“I dunno. It’s kind of gross to say because it sounds a bit like the good old days when everyone went down the boozer. It’s actually f****** horrible. The whole point of it is horrible. It’s driving us to drink to escape the mundanity of our lives. But we won’t do anything to improve our situation and we spend all our days in the pub. It’s no good … Yeah, I spend a lot of time in the pub.”

She probably takes the cloak off when she’s having a pint.

The Bricks That Built The Houses by Kate Tempest is published by Bloomsbury Circus, £14.99. She is appearing at the Aye Write Festival in the Mitchell Library, Glasgow, this Thursday at 6.30pm www.ayewrite.com