Gnomon
by Nick Harkaway
Knopf, 2018

There were flickers and flashes of the fantastic winking all through Nick Harkaway's 2014 novel Tigerman, odd moments when the peripheries of the book's main plot veered well away from the fields we know and then veered promptly back. Now, years later, Harkaway's new novel Gnomon has both its feet planted firmly in the fantastic – this is a big, bristlingly detailed science fiction fantasia whose plots thread and fold back upon themselves and communicate with each other like computer algorithms, if algorithms intended to mystify and captivate instead of misunderstand and hamper. 

The novel is set in a relatively near future in which society has transformed into a totalitarian surveillance state called the System – a state overseen by an all-knowing AI called the Witness. Most people are completely content to live their lives cupped in the hands of this elaborate set-up, but there are dissenters: one of them, an iconoclastic willful Luddite named Diana Hunter, has tried to disconnect herself from the omnipresent umbilicals of the System – which in itself draws the attention of the authorities. When she's brought in for an interrogation and dies in official custody, a state investigator named Mielikki Neith, “an enthusiastic proponent of both the System and the Witness,” is assigned to investigate the extensive memory recordings taken of Diana Hunter – in which she immediately notices hints and dissonances that trigger her detective's instincts. 

She's hardly opened her case when she encounters a suspicious figure and is subjected to a severe beating, and even in the quick description of the aftermath, Harkaway is smoothly deepening the world he's creating:

The pigeons fly up and away, taking the world with them, and then she's half crawling, half lying on the front step of the house. She grasps for the emergency button on her glasses, the one they call the Ave Maria, but her fingers are clumsy and numb. She pulls up a weather forecast for tomorrow, crime statistics for the street – laudably low, well done – and finally fumbles her way to the alarm. She looks for the confirmation signal, and finds a string of messages telling her help is on rthe way, there's no need to press the button. The Witness flagged her for immediate assistance the moment she emerged from the Faraday cage. She knew that. Of course she did. That's the whole point. The Witness is always there. The best friend you could imagine. The only friend you need. 

The throwaway genius of this character moment (“laudably low, well done”) is typical of the book, in which it gradually becomes clear that something is very wrong with the Witness and the society it's shaped, something wrong and perhaps supernatural. Inspector Neith's access to Diana Hunter's memories seems to give her access to other memories as well, including the memories of an obnoxious banker named Constantine Kyriakos (obviously, Harkaway is in high-allegory mode with most of the names in the novel) who achieves a kind of celebrity thanks to an encounter in the Mediterranean with an oddly meditative great white shark:

The moment is possessed of an indifferent perfection: man, water, shark. Nothing else exists. I swim closer, get my photograph. (Not dead. Neither of us. Yet.) Don't quite touch the shark. I'm not going to take liberties. Feel at tugging at my fingertips, a fluttering, like a wind beneath the sea, and my mouth opens in an O. I nearly lose my mouthpiece. The shark is resting in a narrow band of ocean current, a river beneath the sea. 

It's just hanging out, like me. It's a lazy shark. 

Gnomon exults in its complications and imbrications; this is exactly the kind of hyperstimulated ambitious tome that can so often buck its authors off somewhere in the second act, and yet Harkaway keeps the whole thing under perfect – and often maddening – control right to the shock revelations of the final pages. The pleated ingenuity of the plot is reminiscent of Iain Pears' Arcadia, and like that novel, this one will daunt most casual readers and reward its most fervent breadcrumb-following wonks. Gnomon is very much worth the effort: in its fierce intelligence and surprisingly gentle humanity, it's easily Harkaway's most impressive work to date. 

Steve Donoghue was a founding editor of Open Letters Monthly. His book criticism has appeared in the Boston Globe, the Wall Street Journal, and the American Conservative. He writes regularly for the National, the Washington Post, the Vineyard Gazette, and the Christian Science Monitor. His website is http://www.stevedonoghue.com.