J M Ledgard
Jonathan Cape, 208pp, £16.99

"Kismayo, Somalia, 1200 hrs." To open a spy story with a dateline is a cliché - albeit a very efficient one - but not something that J M Ledgard, whose first novel, Giraffe, drew comparisons with T S Eliot and W G Sebald, would ever tolerate. He is a writer painstakingly careful about what is allowed across the threshold of his fiction. Yet Submergence is still, in some ways, a world-spanning spy story. And, in its opening sentence, it somehow needs to do the job of telling us when and where we are. So: "It was a bathroom in an unfinished house in Somalia in the year 2012." But equally Submergence is a hyper-literary novel, and so its every detail is in alignment with the symbolic-magnetic north of the novel. "It was a bathroom" (or water closet) is of the utmost significance.

I teach creative writing. Just about the most frequent question that arises about any piece of writing is: "From what point of view is this being told?" Inevitably, this provokes a follow-up question: "Is everything within this piece of writing consistent with that point of view?" And, if I were asked to define the perspective from which Submergence is told, I would say: "It is told from the vantage point of J M Ledgard, the writer who chose to collect these words, characters, images and facts under the title Submergence."

The reason for this is that no other non-writerly point of view would explain the manner in which this story - this pair of mirrored stories - is told. James More is "an unfortunate spy" who, when we meet him, has been abducted by a small and slightly ramshackle al-Qaeda cell. During his imprisonment and, later, his involuntary tour around the terrorists' badland hideouts and swamp bases, he meditates on his life, his Englishness, his Christianity and his beloved. She, Danny Flinders, is "one of the world's leading researchers on population dyna­mics of microbial life in the oceans".

James and Danny meet only once, in a midwinter present that already feels like a memory, while both of them are seeking solitude at the Hotel Atlantic in France. This snowbound place feels very much out of time, and very much in the money. "The waiters wore tailcoats. Lifting a finger to them was considered gauche; they acknowledged the slightest nod, and glided out of the kitchen like a Greek chorus." It is, for the two main characters, a respite from their anxious, water-obsessed lives. While Danny's research involves trips in submersibles into the far depths of the ocean 3,133 metres down, James is perpetually submerged in his false identity as a water engineer.

In just about their only moment of humour, the terrorists nickname James "Mr Water". They, too, it seems, are aligned with the novel's absolute north - everything that occurs within these pages must relate to liquids.

The novel's point of view is extremely fluid, jumping from style to style, dateline to dateline, person to person. One decision that any writer must make, in attempting to tell a story involving terrorists, is whether to presume to enter their minds. This is the line that Martin Amis crossed, to some derision, in "The Last Days of Muhammad Atta". Submergence briefly dives into the head of Yusuf Mohamud al-Afghani, the cell's leader: "The jihad had been hard. His men had fought Ethiopian soldiers, African Union peacekeepers from Uganda and Burundi, and the Somali Transnational Government troops and its allied militias." This is a deliberately shallow dive, however; and the novel, though sympathetic to the global injus­tices that Yusuf and his brothers are trying to avenge, shows its loyalties in a brief and stark account of the stoning to death of a 14-year-old girl "for adultery, after reporting to the religious authorities that she had been gang-raped".

The writerly perspective is most obvious in what you might call, if you were being slightly mischievous, its "Sebaldesque factoids". These are interspersed through the novel - separated on the page, as each section is, by a long, very wavelike sideways swoosh. Here is the whole of one section: "Extreme cold enables strange things to happen. For example, at the Helsinki University of Technology's low-temperature lab, in 2001, a Bose-Einstein condensate cooled near to the absolute zero of minus 273° Celsius stopped dead a beam of light travelling at 978 million kilometres per hour." This doesn't come from the consciousness of any of the characters. It is Ledgard making his symbolic point. No fluidity; no nothing.

Ultimately Submergence succeeds, and is immensely pleasurable, because Ledgard's magnetic north - though incessantly insisted on - is such an uncanny, inhuman and deathly place. It is a point far below the familiar sea, at the very bottom of the ocean; it is "the hadalpelagic . . . Hadal from the Greek Hades, meaning unseen". This is where we consciousness-addicted human beings are heading as millennial gravity pulls us down. "It will be a submergence. You will take your place in the boiling-hot fissures, among the teeming hordes of nameless micro-organisms that mimic no forms, because they are the foundation of all forms." Including, in some unfathomable way, the form of this wonderful novel.

Toby Litt's latest novel is "King Death" (Penguin, £7 ebook)

This article first appeared in the 08 August 2011 issue of the New Statesman, Slum rule