Kate Corbet is a poor relation, living in the house of her wealthier cousins, the Swansons. Unlike many other historical novels, the Swansons aren't evil; they simply have three unattractive daughters to marry off, and so Kate and the youngest Swanson, Sibyl, are kept out of sight. At a ball one night, however, they overhear a plan to trap Sir Alasdair St Erth into marriage. Kate engineers a way to help him escape from the trap, only for Sir Alasdair to accuse her of trying to trap him herself.
After this inaupicious meeting, Alasdair finds himself wanting to apologise, so he tracks Kate down... and discovers that she is a distant cousin of the Scalbys, a couple on whom he's plotted revenge for years. He blames them for his father's ruin and suicide and, we suspect, probably more too. He has the evidence to destroy them, but he wants to do it publicly, and he thinks that Kate would be the perfect means of getting close to them. So he suggests a deal to Kate: pretending that he needs help to be rehabilitated into polite society, he offers to squire her around to social events she won't get a chance to go to otherwise, if she will help to make him respectable.
Is Alasdair being fair to Kate? His best friend, Leigh, continually urges him to think of her and draw back before Kate gets hurt. In particular, Leigh says, what if she falls in love with him? She won't, Alasdair says - but can he guarantee it? He thinks he can guarantee that he won't have any feelings for her greater than fondness - but can he prevent himself?
The scenes of dialogue between Kate and Alasdair are tremendously enjoyable, and their first kiss - when it finally comes - is explosive. Kate is a fascinating heroine, worldy-wise in so many ways and yet naive in others. Alasdair is coldly cynical, and of course he is using Kate in quite a cold-blooded way, and yet he gradually reveals that he does still have a heart - and a soul.
Where the book began to lose its way, for me, was close to the end, and this is why it gets four stars rather than five. While the final chapter or two of the book - where we finally see Alasdair make his choice between revenge or love, and he almost makes the wrong one, as another review notes - are very well done indeed, the three or so before that just feel like filler, as if we're marching time waiting for the final denouement. Nothing much happens, and I wondered what the point was.
Layton again gives much detail about the London underworld, a feature of some of her earlier Signets and, of course, Gilly's story from her C series. Here, too, I felt that some of it could have been trimmed; we don't need quite so much extraneous information.
In terms of secondary characters, I liked Leigh and Sibyl very much indeed, and I'm hoping that Layton plans a book - or books - about them. However, I see that her next book is about neither. Still, we can hope!