HISTORICAL: EIBHEAR WALSHEreviews The Sealed LetterBy Emma Donoghue Picador, 397pp. £16.99

ALTHOUGH EMMA DONOGHUE is widely known for her novel Room, shortlisted for the Man Booker Prize last year, much of her best writing has been historical fiction, including the bestselling Slammerkin(2000) and the impressive Life Mask(2004). First published in North America in 2008 but now being released in Ireland and the UK for the first time, her new book, The Sealed Letter, is a return to this genre.

Donoghue sets her narrative in the 19th century, drawing on the real-life Codrington divorce case, an acrimonious and widely reported trial in the London of the mid-1860s. Donoghue intertwines the public tussle between Helen Codrington and her older husband, Vice-Admiral Harry Codrington, with an account of the life of Emily “Fido” Faithfull, a successful businesswoman, publisher and pioneer of the early English women’s movement.

Donoghue has published studies as a literary historian, and in this novel she draws on a wealth of archival and documentary research, including newspaper reports, to create her fictional world. As a novelist Donoghue wears her scholarship lightly, using her sources to fill out the missing background of the emotional entanglements and dramas. As part of her task she also knocks a great deal of fun out of her descriptions of London in the 1860s. Here, for example, is an account of Fido’s thoughts about a first-class carriage of the new Underground railway: “White walls, mahogany and mirrors, a good carpet; the carriage is an impersonation of a drawing room . . . The gas globes hanging from the ceiling give off a light that’s wan but bright enough to read by, and a peculiar fume.”

The novel alternates between the imagined viewpoints of husband, wife and devoted friend, caught up in a legal conflict that threatens to overwhelm them. Thus Donoghue convincingly untangles the complications arising from the divorce as the events of the trial unfold.

At the centre of the narrative Donoghue sets up Fido’s unwilling entanglement with the breakup of the Codringtons’ unhappy home. Fido had been the devoted friend of Helen Codrington, and the real drama of the novel begins when the husband sues for divorce. Helen, desperate to see her children, turns to Fido for help in her struggle and is merciless in her demands for assistance.

The Sealed Letteris a lively, readable courtroom drama, convincingly fleshed out and displaying an authorial empathy for wounded, vengeful Harry, charming, duplicitous Helen (something of a Becky Sharp or Lizzie Eustace) and upright, loving, yet easily duped Fido.

Donoghue is fond but unsentimental in her portrayal of the idealistic Fido: “Upstairs, in her bedroom, Fido catches sight of herself in the mirror. Intelligent eyes in the long, upholstered face of – well, there’s no other way to put it – a well-fed dog . . . walking arm and arm with Helen this afternoon, it strikes her that the two of them must have looked like characters from quite different sorts of books.”

As a counterpoint to the painful tussle between husband and wife, Donoghue develops a convincing portrait of the world of early feminism and of the women working with Fido at her Victoria Press, key figures such as Emily Davies and Bessie Parks. With a lightness of touch, the novel makes a point about the cruelty of 19th-century divorce law. Helen, not always a sympathetic heroine, with her lies and manipulations, is nevertheless anguished at the loss of her children and at the law’s remorselessness.

In terms of style, Donoghue moves easily between letters, newspaper reports and third-hand narrative, and the novel mirrors the Victorian sensation novel with the mysterious sealed letter at the core of the drama. We note references, too, to the novels of Mary Elizabeth Braddon, to East Lynneand to the writings of Anthony Trollope. Indeed, Trollope could have written this novel, with his genius for the gradual unfolding of domestic tragedy and courtroom drama. Yet Donoghue underpins her fictionalising with a contemporary sensibility. We see this in her subtle account of Fido's realisation of the truth of her feelings for Helen, feelings Helen is all too happy to exploit. Their relationship is viewed with increasing suspicion when a clergyman's wife, an enemy of Helen, suggests to Harry that "a sinister construction could be put on the behaviour of a woman who, night after night, for months, usurps a husband's place in his wife's bed".

The Sealed Letteris a skilful and pleasing novel, built on solid research but remade into a sympathetic and intriguing courtroom drama.

Eibhear Walshe is a senior lecturer in the school of English at University College Cork. His edition of Elizabeth Bowen's Selected Irish Writingsis published by Cork University Press