The Sealed Letter, By Emma Donoghue

'This is not a sensation novel," a central character reminds herself in Donoghue's homage to those 19th-century women activists who pre-dated the suffragette activities of the Pankhursts.

But, actually, it is a kind of sensation novel, among other things. "Fido" Faithfull is an independent woman of 29, in charge of publishing a progressive women's magazine. One day, she accidentally bumps into her once-adored friend, Helen Codrington, whom she hasn't seen for seven years. Helen has a young officer in tow, Captain Anderson, and it soon transpires that they are having an adulterous affair. When Helen's older husband discovers the truth, he begins divorce proceedings, and bars Helen from seeing their children. Fido is dragged into the sordid court case, where she is called upon either to save, or savage, her friend's reputation. In an echo of Poe's The Purloined Letter, a letter that may or may not be produced is central to the case.

Donoghue has based her historical novel on real-life people and real-life events that make up early feminist history as well as social scandal. Emily Davies is one of many real minor characters at Fido's magazine, and the Codringtons really did have a scandalous divorce, of which Faithfull was a part. But Donoghue expands this collision of feminist history and a piece of notoriety to take a broader and more critical look at the nature of female friendship – Fido's "sisters" at the feminist publishing venture don't stand by her during the trial, fearing that the negative publicity attached to her will rub off on them. And Helen reveals herself to be a duplicitous kind of woman in more than her relationship with her husband. It's not a pretty picture of female solidarity.

In drawing on those "sensation" novels by Mary Braddon and Wilkie Collins – her plain heroine is almost a parody of The Woman in White's Marian – where the reputation of women was at stake in plots involving divorce and adultery, Donoghue replicates their breathless pace and builds a sense of expectation. But the overall tone is oddly light, as though we are expected to find Helen and Fido's situation amusing, even silly. It's almost as though in parodying writers she nevertheless clearly loves, Donoghue can't quite take herself seriously, or her characters. As a result, this is a very enjoyable, and, in places, even educational, kind of romp. But I'm not sure that's really what she intended.