FICTION: Your Face Tomorrow 3: Poison, Shadow and Farewell by Javier Marias. Translated by Margaret Jull Costa

AMONGST contemporary Hispanic writers, Javier Marías is undoubtedly the best known and quickest into English translation, which is no mean feat. Chilean Roberto Bolaño, whose evaluation of Marías as "by far, Spain's best writer today" is emblazoned on the cover of Your Face Tomorrow 3,is a case in point: his The Savage Detectivescame out in 1998 and was hailed a Latin American literary sensation, but did not appear in English until 2007. Bolaño's masterpiece, 2666, fared somewhat better, being published posthumously in Spanish in 2004 and waiting only four years for an English rendering.

But it’s not just that Marías is lucky; his nostalgic fascination with a stage-Englishness, allied to a “Big Brother” spy narrative characterised by an uneasy tension between dark comedy and gratuitous violence, clearly appeals to literary publics well beyond his home country.

Marías is the son of Julián Marías, a well-known Spanish philosopher and disciple of José Ortega y Gasset. As a young writer, Javier Marías spent a short time lecturing at Oxford, which featured in his first major book, All Souls. In the 1990s, Marías went on to write three excellent novels: A Heart so White, Tomorrow in the Battle Think on Me, and Dark Back of Time. In 2002, he published the first of the Your Face Tomorrowvolumes, which he describes as a novel "in three parts" rather than a trilogy. Each instalment has appeared to almost unanimous critical acclaim, and in 2008 Marías became a member of the Spanish Royal Academy.

A long, torturous narrative, Your Face Tomorrow 3offers few concessions to the reader, as Marías himself admits. As with the previous volumes, the subtitle – Poison, Shadow and Farewell– sets up central motifs around which Marías spins meandering and frequently claustrophobic meditations on life, death (usually of a violent and untimely nature), heroism and cowardice.

This final volume continues the tale of the pretentious Jacques Deza and his involvement with a shady London intelligence unit run by odious Bertram Tupra. Tapping into the same fascination with a technological and voyeuristic "dark side" to society that drives such series as the BBC's Spooks, Marías self-consciously evokes a whole tradition of English spy stories, including Fleming and Le Carré, but is quite different in his handling of narrative form: there is no plot-driven insistence on tension and denouement, or evil and its revelation. Instead, we are treated to a whimsical wander through the minds of Deza and Tupra as they touch on such themes as love, violence, and betrayal.

One model behind this is clearly Laurence Sterne's Tristram Shandy, to which Marías frequently alludes. But whilst Sterne's eponymous hero observes wryly, "Writing, when properly managed (as you may be sure I think mine is), is but a different name for conversation", Marías's character Sir Peter Wheeler is more prosaic: "Talking and talking, without stopping, that is the one thing for which no one ever lacks ammunition. That is the wheel that moves the world". What in Sterne is delightful wit often becomes, in Marías, simply tiresome. His insistent references to English popular culture are a good example: in one paragraph Peter Pan, My Fair Ladyand Dickens are all quickly roped into the task of demonstrating Deza's earnest desire to portray Tupra's world.

Marías's exuberant meanderings and dizzying constellation of themes are perhaps closest, in Hispanic writing, precisely to 2666, but Marías does not write with Bolaño's sense of purpose and human empathy, nor does he have his sensitivity to the discursive possibilities raised by constant transgressions of the border between documentary form and imaginative fiction. Marías's distanced observations of character are too cerebral and offer nothing to match the new moral sensibility that Bolaño's writing conveys. Like many contemporary Spanish writers concerned with the themes of war and violence, Marías begins by asking what heroism and cowardice might mean in today's world, but this latest novel – despite being, in turns, entertaining, ironic, preposterous, and exhibitionist – offers a rather bleak view of humanity.

In reviewing Your Face Tomorrow 1, I reserved judgement until the work was finished. That opening volume raised a series of important issues concerning our perception of the past, frequent lack of understanding of human motivation, and the metaphor of the writer as a spy or voyeur investigating the present as a means of predicting the future. All these themes remain central to Marías's latest book, as does his focus on language, translation, and cultural contact. When at his most focused and polished, Marías is certainly a very powerful writer, but too often in Your Face Tomorrow 3a directionless excess dominates, leaving the work's initial promise curiously unfulfilled.

Alison Ribeiro de Menezes lectures in Spanish and Portuguese at UCD. Her latest book, War and Memory in Contemporary Spain, edited with Roberta Quance and Anne Walsh, appeared with the Spanish publisher Verbum earlier this year