A panopticon is a circular prison or detention centre conceived in the 18th century by English social theorist Jeremy Bentham. The structure was designed to place inmates in rooms laid out in a ring facing inwards, so that wardens in a central tower or 'inspection house' could observe them at all times, without being seen themselves.

Bentham believed the panopticon to be "a mill for grinding rogues honest," and while he did attempt to develop these structures as care-centres and hospitals too, his focus was mainly on developing a secure prison. The idea didn't really take off but the concept provided one of Granta's Best British Novelists 2013, Jenni Fagan, with the perfect location for her novel.

The Panopticon is told entirely from the perspective of Anais, a 15-year-old young offender who has bounced in and out of care her entire life. She has no relatives and her only vaguely parental figure was an adoptive mother, Teresa, a prostitute who was found brutally slain in her bathtub while Anais waited for her in the living room of the same flat, not knowing what had happened.

Anais relies on drugs to ease her through life, and often she sees things. Perhaps she imagines them or hallucinates them, perhaps they are a fabulist version of her truth: "I've seen plenty of s**t other people couldnae see and I knew it was real." Having no familial ties at all, she convinces herself that she is an experiment, created "from a bit of bacteria in a Petri dish" and that she is constantly being watched to "see exactly how much ... a nobody from nowhere can take."

Fagan sets up The Panopticon with this idea, establishing firmly a strange sense of almost Ballardian unease: "I'm an experiment," reads the very start of the book, "I always have been. It's a given, a liberty, a fact. They watch me. Not just in school or social-work reviews, court or police cells - they watch everywhere." Very often, Anais' perspective is skewed by any number of drugs she is constantly consuming, her imagination running wild and her paranoia running deep. Of course, all this does is make her more interesting and her world more arresting.

Many times, both the fascination and the horror lies in Anais' casual references to prostitution, rape, drugs and what seems to be her own complete disregard for her safety, and the very similar attitude of the girls she befriends at the detention centre. Perhaps, like any teenager, she believes herself to be invulnerable; perhaps she simply believes she has gained enough experience to survive anything at all. But eventually, Anais is a complicated teen in deep trouble who does not want to ask for help, leading to a particularly horrific incident. This may be the story of a young ward of the state who wants desperately to have a better life, and while there is much conflict, there is also a sense of resolution.

Some may say that Anais is everything taxpayers resent about young offenders - she has no desire to go to school, her casual attitude towards unsafe sex, drug consumption and sale is alarming, she has a nasty violent streak she has no qualms about showing, she seems to have little remorse for the pain or trauma she has caused others and most recently, she may even have put a policewoman into a coma. She hates to say please or thank you. On the surface, Anais is everything you wouldn't want to run into in a dark alley, everything you wouldn't want your own child to meet or be. On the surface, she could be straight out of A Clockwork Orange.

But Anais is also a wonderful, immensely likeable protagonist - smart, fiercely loyal, sensitive, full of teenage angst, dreams, hopes and despair. In her, Fagan has created an incredibly true and memorable voice. Anais may appear to her care workers to be irreverent, disrespectful and completely beyond help, but in Fagan's distinct, strong first-person narrative, it is easy to see that this is a teenager who can be more than she has been allowed to be. "I'm so imperfect, it's offensive," says Anais, but it is in these imperfections that she truly shines, and through her voice, The Panopticon does too.

Fagan freely uses Midlothian brogue in The Panopticon, along with liberally peppering Anais' narrative with a variety of colourful curses. As arresting as Fagan's use of language is, as much skill as she has over Anais' voice and narrative, it must be said that The Panopticon is not for those offended by swearing, violence or sex. Fagan is never gratuitous, but she does not shy away from the ugliness in the lives of these young people either. Bad things happen, but the narrative never flags in quality. There is a strong balance of the grotesque and the beautiful in The Panopticon, with Fagan's experience as a poet often coming clearly through. This is a book that ferociously defends those on the margins of society, those unable to break free of the system, but it is also a book that does not flinch from the truths behind the same system. "I'm an orphan," says Anais. "There are far worse things a girl can be." And this girl, Fagan's heartbreaking "girl with a shark's heart," struggles for what many would never appreciate: "just a plain ordinary life."

The Panopticon

(Novel)

By Jenni Fagan

Windmill Books, UK

ISBN 9780434021772

304pp.