Books: The butterfly hunter's iron lady

VLADIMIR NABOKOV was a great performer, and perhaps his most marvellous trick was to marry an audience. Vera Slonim was a girl from a Jewish family in his home town of St Petersburg; they met in Berlin, and married there in 1925. Their union lasted over half a century and became one of the most formidable double-acts in the history of literature. Vladimir was the master magician; Vera was his manager-muse. When the need arose, she was also the police.

Stacy Schiff had access to the hundreds of letters that Vera wrote on Vladimir's behalf to publishers, family, friends, translators. She has analysed every episode of their tormented migrations, Russia to Berlin to Paris to America. She writes with a lucidity and an elegance that chimes beautifully with the Nabokovian tale she has to tell.

Vera's was the electricity behind the scenes. In the Great Nabokov Roadshow, she took care of the box-office, wardrobe, fans and make-up. When critics in the cheap seats failed to applaud the genius of her husband, Vera was the bouncer who threw them out. Tall, white-haired, formidable, omnipresent, unforgettable and often terrifying to those who met her, she somehow also managed to vanish into the background - or rather, she was the background.

Vera did the things her husband did not - and there were a lot of things Nabokov didn't do. She did the family, the driving, the letters, the lawyers, the tax people, the bores and the money. She packed a pistol to protect him from rattlesnakes when he went hunting butterflies in Texas. She went to war with publishers, decapitated biographers and vaporised journalists.

Vera was not his first love .But for her steely watchfuness, she might not have been his last. In time they merged so completely it was impossible to tell where "VN" began and Mrs Vladimir Nabokov ended. There were those who wondered if she wrote the books, too. An idea Vera scornfully dismissed: she was, she insisted, merely the facilitator. VN was the stagecoach with the bullion; she simply rode shotgun. Pnin and Lolita are Nabokov's creations; but the rise and rise of Mr Nabokov was Vera's life's work. But she did her best to make sure it didn't show.

This cool and delectable study is all the more remarkable for being a portrait of an invisible woman. Sensibly, for one compiling the life of such a presence, Stacy Schiff has concentrated on concrete details that reveal the outline of the absent one: the hat on the mantle-piece; the letter in the hall; the women Vladimir loved but didn't marry. She measures Vera's impact rather as one measures the effect of gravity, or invisible particles, by their impact on distant visible bodies.

Schiff is particularly good on the American years when home became anywhere you could hang a butterfly net . Mr and Mrs Nabokov spent most of their lives on the run; from revolutionary Russia, fascist Berlin and then France, as the Nazis closed in. Even the famous penthouse in a Montreux hotel was simply a good hide-out.

The Nabokovs landed in America in 1940, broke, foreign and unknown. Vladimir got a job as Wellesley College where he taught Russian studies. It was in the American years that Vladimir and Vera perfected their act. People learnt not to invite other guests when they came to dinner. "He buffooned, and she was combative - overeager to remind the assembled guests of her husband's greatness." Vladimir was the eccentric genius, with a roving eye for his students. Vera was the sidekick from hell. Other people were surplus to requirements.

Schiff is refreshingly calm about Nabokov's appreciation of his female students. Vera denied or ignored them. But his mild advances would go down as date-rape in America today. Schiff shows a restraint in describing his amours which is positively scandalous in these exhibitionist times.

This is admirable but odd, since Nabokov's fiction is one of the few truly erogenous zones in English-language letters. He is the magician who teased words into a kind of tumescence that still disturbs; the inventor of Lolita, who in only her second film incarnation has found herself persona non grata in the country where she was born.

Perhaps the biographer has caught something of Vera's conflicting moral values. She thought Lolita a very moral book. Yet she refused to allow her son Dimitri to read Tom Sawyer because it might have got him thinking too early about young girls.

On the central question: did Nabokov like little girls? Schiff is abolutely clear. She quotes one of them, an almost-nymphet from Wellesley, with whom Nabokov had a flirtatious affair: "He did like young girls. Just not little girls."

This is Vera's book. One feels her presence in this wonderfully acute and delicate study - and sees her shadow on the wall. But Vladimir steals the show. Vera spent her life making sure he did.

Christopher Hope's `Signs of the Heart' is published by Macmillan