This gem of a book just come as a joy to readers who were disappointed by last year's unearthing of The Original of Laura, Vladimir Nabokov's unfinished final novel. As Michael Maar suggests in Speak, Nabokov, the leftover notes for Laura (which Nabokov ordered to be destroyed shortly before his death in July 1977) were grimly revelatory of the author's obsession with sexual desire, rather than an artistic treat. Speak, Nabokov steers a course between passing candour about the man and sophistication. It is a startling piece of literary detective work, which deciphers the word games and patterns that permeate Nabokov's novels in order to throw light on the author's life.
Nabokov worked with the tension between evil and innocence. Born in St Petersburg in 1899 and forced to flee the Russian Revolution in 1917, his writing life began when his father was accidentally assassinated by Bolshevik agents hunting a more important target in Berlin in 1922. Episodes like this, which found their way into his fiction, were typical of the "horror" Maar identifies in Nabokov's writing. Against this, Maar sets the "shimmer", a view of the world shot through with mysterious presences and coincidences, manifestations of light and shade, colour and shape.
The shimmer suggested at best a distant happiness and at worst a joyous self-deceit. Nabokov's preoccupation with the other world was imaginative, not religious. Maar shows the affinities with gnosticism - a dark world permeated by sparks of light - and with Schopenhauer, who thought that art gave glimpses of goodness and release from human evil.
When, in 1958, Nabokov sold the film rights to his novel Lolita, a succès de scandale about a literary scholar's seduction of a 12-year-old
girl, it made him so rich that he and his wife lived for the rest of their lives in a Swiss hotel. Such success should have come to him 30 years earlier, Nabokov grudgingly insisted. And who, rereading his novel Invitation to a Beheading (1935-36), for example, could doubt that he was right? As Nabokov transformed the political nightmare that had gripped Russia into a fairy tale; the comparisons with Kafka were inevitable. The novel depicted the murderous power-seekers as ugly, empty buffoons and took up the inner life of their victim, Cincinnatus C, as if he were a babe in arms.
When biographers and critics probe behind the scenes of works of art, they risk turning devoted readers into disenchanted gossips. This kind of criticism undermines the artistic status of fiction. Maar does the opposite. He wants to show us how "the depths are hidden on the surface of the plot". Nabokov wraps his experiences as a Russian émigré in Berlin, and, later, teaching in America at Cornell University, in a veil of symbols and signs. Webs of enchantment envelop sympathetic characters such as the Russian teacher who is the eponymous hero of the novel Pnin. The names of the things encountered by Timofey Pnin - people, a squirrel, even a moth in his classroom - create a correlative of the sweet inner life. No proper name is not symbolic in some language that Nabokov knew; and the acrostics he built in to his texts remind us that, in Germany, his first job was compiling crosswords.
Much else in Nabokov's work acts as an extended inquiry into how literature can express sexual torment and not lose its own magic. After an early experience with a homosexual uncle, Nabokov despised same-sex love. As for women, he venerated a few, but otherwise saw them as evil temptresses. Margot in Laughter in the Dark, Mariette in Bend Sinister and Liza, the wife who abandons Pnin, were devils on a par with Humbert Humbert, Lolita's seducer.
Why have Nabokov's enchanting novels and stories not aged? One factor is his almost total disdain for social questions and historical background. Another form of Nabokov's genius, Maar argues, in an analysis of The Real Life of Sebastian Knight, are the micro-plots beneath the surface of the main plot.
With sentences such as "one usually reads past the devil, because he masks himself in idiom", Maar is no mean enchanter himself.
Lesley Chamberlain is the author of "Nietzsche in Turin" (Quartet)
Verso, 160pp, £14.99