Review: The Paris Winter, By Imogen Robertson. Headline, £14.99 As a writer of historical thrillers, Imogen Robertson's reputation is beginning to outpace most of her rivals'. The Paris Winter is quite as accomplished as her earlier books. But there is a canny Robertson strategy, also evident in the previous novel Anatomy of Murder, which employed a radical shift of gears. The opening section of that book started as a rumbustious naval adventure in the tradition of such writers as Patrick O'Brian, before settling into its comfort zone of malign deeds in the malodorous streets of London. Similarly, The Paris Winter begins as an elegant Henry James-style novel of class and manners, with an innocent abroad finding herself up against more worldly (and corrupt) foreigners; the naïf here is an impoverished young English girl. But suddenly the narrative (with its adroit evocation of early 20th-century Paris) has a bone-shaking twist. We move from a novel of art and character into a stygian, edgy thriller. If this makes the novel sound broken-backed, that is certainly not the case. As in her earlier work, Robertson absolutely justifies her tactics. Maud Heighton escapes from a stifling Darlington and joins the celebrated Lafond Academie in Paris: an unorthodox group of young women art students in a cloistered, all-female environment. But while Maud finesses her artistic skills, she lives in the most desperate poverty. Then a glamorous and exotic fellow-student, the wealthy Russian Tanya, opens the door for her to become the companion to Sylvie Morrel. Maud begins to believe her luck has turned. But Sylvie is an opium addict, and the secret world she moves in begins to pull Maud into its embrace - and she is singularly ill-equipped to deal with the dangers she encounters. The period detail here is impeccable, with the reader transported into the exhilarating Paris of Manet and the Belle Époque. But what is perhaps more developed is Robertson's subtle and nuanced grasp of character, notably of the vulnerable Maud: a heroine almost worthy of Thomas Hardy. It is this characterisation - as much as the narrative - that lifts The Paris Winter into a category of its own.