As The New York Times describes it, North's book is a gripping suspense read, an aching meditation on loneliness and a brutally cynical examination of modern media.

It is also a critique of the cult of celebrity, and a cautionary tale for millions of Facebook and Twitter users who surrender personal data with scant heed for their privacy.

North's sassy protagonist, Hope Arden – part computer-hacker Lisbeth Salander, part crusader Buffy – is a forgettable thief. At 16, she begins inexplicably to fade from the memory of loved ones: her father forgets to drive her to school, her mother sets the table for three, not four. A teacher forgets to chase missing homework.

Arden takes to crime to survive and be remembered, and when she steals a famous diamond from a Saudi princess she makes an enemy of the creators of a sinister life-coaching app.

Perfection burrows into subscribers' bank accounts and purchasing records, monitors kilojoule intake and offers bonus points, discounts from in-app suppliers and treatments to transform the overweight and under-confident into thinner, more charismatic selves. Elite membership is a Faustian bargain.

Both The Sudden Appearance of Hope and North's breakthrough bestseller about identity and resurrection, The First Fifteen Lives of Harry August, soon to be made into a film, fall in the genre of science fiction. But the complex algorithms for an app like Perfection are not such a big step away.

"It's a question of what you do with that data," she says when asked if this Big Brother-ish monitoring is something to fear. "It's a question with what you do with surveillance, it's a question of what you do with the knowledge you gather on people."

North is the pseudonym of Catherine Webb, a British author who also writes adult fantasy under the name Kate Griffin. The pseudonyms were the idea of her publisher to draw a distinction between the eight children's and young adult fantasy novels, the six adult fantasy novels and the three science fiction books and short story collection published since she was 14. She is now 30.

An only child, North was a precocious teen reader who began her first book, Mirror Dreams, about a boy who lives in dreams, when she had reached "the bottom of the fantasy bookshelf in my local library".

Her father was a book editor, Nick Webb. "He turned around and said, 'This book probably won't sell'," North recalls."'You should assume nothing is going to come of it but it's not as crap as it could be so you should send it to a literary agent; this is the name of a literary agent I've known for many, many years who will at least give you a hearing. So try her.'

"I did, and she's been my agent ever since and that single act, of finding an agent who is sympathetic to who you are, changed my life forever, and that was very much [thanks to] my dad. That's probably the single and greatest thing he ever did for my career."

In 2004 and 2006 North was nominated for the prestigious Carnegie Medal, recognising outstanding children's writing, for Timekeepers and The Extraordinary and Unusual Adventures of Horatio Lyle respectively.

Both times, North was in the middle of university exams at the London School of Economics. Her parents impressed on her the fleetingness of such honours without a back-up plan. After earning a degree in history North switched to the Royal Academy of Dramatic Art, graduating in 2010 as a theatre lighting designer.

Between books, North spends time in darkened rooms trying to wrestle the soaring ambitions of stage directors into modest budgets.

"Very different parts of the brain get used," says North of her two professional lives. "In theatre I have to do a lot of maths and angles and order stuff and negotiate logistics and spend an awful lot of time taking notes and looking vaguely switched on, and programming and making pretty pictures out of light and also climbing ladders. Whereas books; it's just me in a room writing, and it's quite nice to have distance really."

North is only half joking when she suggests The Sudden Appearance of Hope Arden could be subtitled "Technicians: no one knows they exist".

"You do acquire a kind of invisibility," she says. "I've been in plays where at the end the crew and cast have a massive party and they'll thank everyone – they'll thank each other, they'll thank the director, they'll thank the dog, they'll thank their parents and they'll fail to even remember the group of people at the back of the room who work 13 hours a day for eight weeks to try and get their show to an acceptable standard."

The Sudden Appearance of Hope
Claire North
Orbit, $32.99