THE novel of World War One France that still informs most opinion on Sebastian Faulks, Birdsong, is now 14 years old.

No surprise, then, that this novelist should be seeking to depart from the themes and narrative modus operandi that made his name; Human Traces, published in 2005, ranged across psychoanalysis and evolution and was full of ideas. Now comes another departure. This closeted, strange first-person narrative takes aim at truth via the seemingly prosaic life of Mike Engleby, from youth to middle age. Faulks has a message, here, about consciousness, and identity; but Engleby works best when Faulks leaves ideas aside.

We join our protagonist as an English student in '70s Cambridge. Faulks has a wonderful ability to evoke time and place.

Engleby's world is one of muffled sexual longing and folk rock evenings in the student bar, all perfectly rendered. We learn, quickly, that he is awkward and socially aloof; his obsession with the attractive Jen seems typical undergrad melancholia. But then Jen disappears in mysterious circumstances. Engleby heads into '80s London and journalism; but the strange vanishing haunts the rest of this novel.

Faulks has created in Mike Engleby an inner world full of persuasively idiosyncratic and delicate observations; when he says that Jen "sounds as though she's always trying to suppress laughter out of consideration for the person she's talking to", that captures precisely a certain kind of middleclass female voice, and also the close, near-fetishistic observation of a lover. However, his attempts to inject a wider historical significance can clunk. We're told to read this novel in part as "a lament to a generation", but passages such as those on the fall of the print unions, and on how London's trendy "Notting Hill is the coming place", seem only a tacked-on, unsuccessful attempt to fulfil that remit.

We come to see that Engleby is not what he seems. He finds a girlfriend, and takes a job at a broadsheet, interviewing novelist and perjuror Jeffrey Archer and Conservative MP and hedonist Alan Clarke. But there are attacks of mental disturbance, vividly handled by Faulks: "The centripetal force of Engleby failed and I began to fly apart, into my atomic pieces." Engleby pores over Jen's diary, stolen from her Cambridge room. It is a high fictive challenge to reveal the true nature of a selfdeceiving protagonist via a firstperson narrative; one is reminded of the artful, restrained novels of Ishiguro. Faulks, here, doesn't achieve that kind of quiet, epiphanic power. Nevertheless, the pages keep turning: what has Engleby hidden from us?

Engleby proves a subtle, perceptive work, and a compelling read.

Ultimately, Faulks's gestures towards a view of human consciousness are less successful; he ends up, in this book's latter stages, having to spell out his message that "the defining human faculty - that of self-awareness - is a faulty one".

Still, Faulks's mastery does not desert him. The final passages, free of grand authorial ideas and faithful, instead, to the experience of Engleby and Jen, are thrillingly moving. Most novelists will never write lines that speak to the heart so effectively; for Faulks that seems the easiest thing of all.