In 1864, divorce was still rare in Britain (as elsewhere), and the real one that Emma Donoghue forensically reconstructs in her new novel was a national scandal. The wronged vice-admiral Henry Codrington and his sexually predacious wife were already magnets for the prurient. Add in, as a witness to the case, the famous feminist Emily Faithfull and veiled hints of lesbianism, and public horror knew no bounds.

Donoghue recreates grim 19th-century London – relieved by whiffs of exotic Malta – with vividness and authority....What could have been mere Victorian melodrama resonates here with emotional truth.

As with Donoghue's previous novels "Slammerkin" and "Life Mask," the plot is psychologically informed, fast paced and eminently readable (it compresses the timeline of actual events). Yet some narrative elements borrow too much from the 19th century. Exposition often comes packaged in dialogue, where it sounds artificial:....Good lines there are in abundance. And in the end, "The Sealed Letter" provides both the titillating entertainment readers like Helen and Fido crave and the more sober exploration of truth, commitment and betrayal Harry might appreciate. Donoghue's sympathy for all three of her central characters emerges through intimate narration and lifts the novel out of the tabloid muck, despite the public shaming Harry, Helen and Fido experience. There is, as Fido puts it, "so much to say, and little of it speakable."

Briskly written, deftly plotted and nicely ironic, The Sealed Letter falters only in the absolute gratuitousness of some of its period detail.... Some of the slang, too, looks a touch anachronistic. "Deb" is at least 60 years before its time. And would a well-bred woman of the 1860s talk about someone "walking out" of their marriage? None of this in the least detracts from the bounce and sparkle of The Sealed Letter's narrative line.