Javier Marías is a novelist who requires both the reader's willing surrender and their consistent alertness. These, in a sense, are also the qualities required by his narrator, Jacques Deza, an erudite and cultured Spaniard living in London and working for a clandestine intelligence organisation in, as he frequently remarks, a building with no name. In the previous two volumes of Your Face Tomorrow - this one, the longest, forms the conclusion to a trilogy - Deza has described his recruitment into what the enigmatic Bertram Tupra also refers to as "the group"; and, latterly, a shocking incident at a nightclub in which Tupra, with Deza as his witness and reluctant helpmeet, beats and terrifies a lascivious and buffoonish Spanish diplomat, using a fearsome, double-edged landsknecht sword. Tupra's question to a horrified Deza both concludes the second volume and opens the third: "But why, according to you, can't one do that? Why can't one go around beating up people and killing them?"
If the question sounds straightforward enough, Deza finds his response to be anything but; and, as this novel unfolds, like its predecessors, by means of lengthy, looping digressions, narrative swerves and unexpected interventions from a past both real and imagined, the reader finds himself on similarly unsteady ground. Marías's prose style - unhurried but taut enough never to feel leisurely; self-consciously pedantic, determined to turn over each incident it animates until it can yield no more nuance or information - is both mesmerising and ingeniously frustrating, as if the author had set himself the task of teaching us how to read properly. If his setting is, tangentially, the world of espionage, he is nonetheless a million miles away from the instant gratification of the thriller writer.
Deza (who also features as Jaime, Jacobo and Jack) has been singled out by Tupra (on occasion Reresby, Dundas and Ure) because of his ability to intuit from people's faces and behaviour today what they might be capable of doing tomorrow; whether, for example, an apparently upstanding member of society might be able, in future, to commit acts of treachery, deception or brutality. The use to which Deza's impressions are put - these are constructed like novels, he reflects, or perhaps short biographical studies - is largely unknown, to him and to us, though the general idea is suggested when Tupra shows him a series of explicit films in which prominent figures are caught in hideously compromising situations, often either as witnesses to or perpetrators of extreme violence.
Deza's initial response - one that might form the basis of his reply to Tupra's question - is one of disgust, and a wholesale rejection of his superior's methods. But it is no coincidence that what Deza watches at the nightclub and on the screen is the "poison" of the title, with its implication of contamination and contagion. Shortly afterwards, when Deza believes that his estranged wife, Luisa, is being beaten up by a new boyfriend, his memories of both episodes suggest to him a way, in Tupra's words, to "get rid of the problem". Whether or not Deza is capable of taking on Tupra's qualities - whether violence was ever in his face yesterday, and whether he can persuade himself of the idea that a greater harm will be averted by his actions - is what the novel goes on to explore.
There is much else besides; in addition to the almost jokily lowbrow cultural diversions, Marías also continues his adept weaving of the contemporary narrative into his exhaustively minute and evocative explorations of recent European history and, in particular, the Spanish civil war. But although he frequently makes use of historical sources, even to the point of including facsimile reproductions of documents and photographs, what he is attempting here is something closer to an occult history - a partial, painful understanding of the emotional and psychological effect of war on an entire society and its descendants. Deza's current preoccupations, even at their most domestic, come to seem part of a continuum, of an endless human struggle to balance action against consequence, desire against the risks of its fulfilment, of the complexity of unpicking motive.
Marías's triumph, in a suite of works that stands as one of the most ambitious and original in recent years, is to show us that fiction can derive its power from allowing itself to be profoundly associative and to exist on more than one plane of connotation. It is not surprising that Marías is a translator of Laurence Sterne; rejecting the linear, his writing comes closer to explaining to us the way our memories make a mockery of yesterday and tomorrow, and of how what we think we see in our own faces may be nothing more than a trick of the mirror.