Balthasar's Odyssey, by Amin Maalouf, trans. Barbara Bray

Amin Maalouf's enchanting new novel, set in the mid-17th century, traces the picaresque adventures of a bookseller named Balthasar Embriaco from Constantinople (Istanbul) to Genoa via London. Maalouf avoids the usual pitfalls of the historical novel. No faux realism for him: he eschews all exotic description, as he spares us any embarrassing attempt at the historic vernacular. He keeps dialogue to a minimum, concentrating instead on his protagonist's inner world, and employs plain language.

The narrative is cast in diary form, since Balthasar cannot be sure whom to trust and so needs to invent a confidant. His journal is both a meditation on the need for Christians, Muslims and Jews to tolerate each other and a fantastic travelogue. The excellent, supple translation from the French by Barbara Bray chimes in perfectly, making Balthasar sound as much modern as pleasingly strange. Bray has produced a prose as clear as water, and as refreshing.

Balthasar's journey follows classic trade routes across the Mediterranean. Our bibliophile hero is in hot pursuit of a lost book, The Hundredth Name, that he has allowed to slip out of his hands. This sacred text with magical properties, revealing the single name of God stopped short of in the Koran, protects its fortunate owner from all disaster.

The elusive book bobs always just ahead of us in the story, like one of those purloined letters beloved of 18th-century novelists, like a meaning or a main clause endlessly deferred. The quest to recapture it forces Balthasar into intellectual, religious and emotional speculation and upheaval.

We're in 1666, which is perhaps the Year of the Beast in the Apocalypse: "It is easy to see the attraction of a book that claims to reveal such a secret nowadays, when men live in fear of another Deluge."

Balthasar is compassionate, witty and honest, an utterly charming narrator, who uses his diary not only to record his wanderings but also to reveal his worries, guilts and insecurities: "As I write these lines my doubts increase, as if my pen, scratching at the paper, was also scratching at the wounds to my self-esteem".

Enduring mysterious attacks, traps, ambushes and beatings, Balthasar is also tested by the growth of his love and desire for Marta, the runaway woman who has joined his party and whom he feels obliged to help. Since Marta is assumed by innkeepers to be his wife, he chivalrously continues this deception in order to protect her honour. Tucked up in bed, they make the shyest, and sexiest, of advances: "I didn't hold her hand until our second meeting, and even then I blushed for it in the dark. At this, our third encounter, I put my arm round her shoulder. And again I blushed for it. She raised her head, undid her hair, and spread the black tresses over my bare arm. Then she went to sleep without saying a word." Two months later, he's murmuring endearments in Italian entwined with Arabic as he entwines her body with his own: "every act of love is different ... Now she's both tender and passionate. Her arms enfold you like those of someone swimming for dear life; she breathes as if her head had been under water till now". Soon Balthasar is buying his beloved lengths of silk, shoes, and bottles of scent: "Is it vain of me to play the generous fiancé, spending money in a lordly fashion? ... It is up to a man to dress the woman he undresses and to perfume the woman he embraces."

Jane Eyre reproaching Mr Rochester for his show-off engagement presents springs irresistibly to mind. The lady vanishes all too soon, however, and the irrepressible Balthasar consoles himself with golden-hearted Bess in a tavern near St Paul's, whence he watches the spread of the Great Fire. Sparkling and erudite, this is a wonderful novel.

Michèle Roberts's new stories, 'Playing Sardines', are published by Virago