On board a packet ship returning to England from a visit to Ireland, Adam Vickery, the Marquess of Tannerton, observes a woman who is prisoner to a Bow Street Runner. The ship founders, and the Runner callously takes the last place in the boat, leaving the woman to die. Tanner has guilt issues; he feels responsible for several deaths that took place the year before year (described in Innocence and Impropriety, which you needn’t have read to follow The Vanishing Viscountess's plot), so he does all he can to save the woman, and they wash up on a Welsh beach together. The lady calls herself “Miss Brown” and informs Tanner that she is on the run because of a jewel theft she was framed for. Her immediate destination is Edinburgh, and because he feels responsible for the life he saved, to atone for what happened last year, and not least because he is instantly attracted to the woman, Tanner insists on accompanying her until she has reached safety.

Tanner is an attractive hero. Both chivalrous and responsible, he has no plans to seduce the mysterious lady, although he wouldn’t mind if she made a first move. He is also happy to travel anonymously and does without the trappings of wealth and title with perfect cheer. To confound pursuit, they ride across country, posing as an estate manager and his wife.

“Miss Brown” is really Marlena, the widowed Viscountess Corland, and Baroness Parronley in her own right. Three years earlier her cousin Lord Wexin framed her for murdering her philandering husband. There was a witness - a maidservant from near Marlena's home of Perronley in Scotland - but she was threatened by the murderer and vanished. Marlena herself escaped certain conviction and execution by seeking shelter with her friend Eliza in Ireland. There she was discovered, but as Eliza and her children were sick of a fever at that time, Marlena could not leave them and finally got arrested at Eliza’s graveside. Now she hopes to find anonymity and a new life in Edinburgh. Tanner repeatedly offers to take her to London and help to prove her innocence, using all his influence as a marquess and friend of the Prince Regent, but she is afraid he would be tried as an accessory and face the death penalty just as she does, so she is adamant in refusing to tell him the truth or to let him help her.

The romance progresses smoothly and is very sweet. Marlena, for a pleasant change from all those unawakened widows, enjoyed sex in her marriage before it deteriorated, and she is hungry for sex as is Tanner. In fact it is she who initiates their first encounter, and the love scenes are romantic and satisfying. In addition, both characters think (for different reasons) that they will not find love, and it’s pleasant to read about their slow realization they might just have stumbled across it.

Whereas I was happy with the romance plot, I was not so with the mystery, and especially with Marlena’s plans for her future. In fact, her attitude proves her TSTL. If she has no hope whatsoever of ever clearing her name, why on earth doesn’t she ask Tanner for some money and a ticket on the next boat to America while they are in Liverpool? She was discovered in the wilds of Ireland, so what makes her assume she will be any safer in busy Edinburgh? On the other hand, Tanner is a powerful and rich marquess, so he might be her one chance in a million, someone who might assist her in locating the missing witness and protecting said witness against the villain’s threats. I also didn't buy her fear that Tanner would be hanged along with her. Yes, she read in a newspaper that anyone who helped her would be hanged. But then her friend’s husband, who sheltered her (albeit unknowingly) for three years, seems to have escaped hanging. As for the marquess’s possible influence in helping Marlena, the first two persons of authority Tanner informs of her innocence believe him within five minutes flat and become her devoted champions. Gee, who would have thought?

In addition, events in the second half of the novel depend far too much on coincidence for my taste. The tracking powers of one single Bow Street Runner all across the north of England are nothing short of miraculous. In a secondary plotline, a secondary character is offered a strong shoulder, love and support by a delightful man but turns him down in a manner that is tiresomely similar to that of Marlena.

What is especially aggravating about The Vanishing Viscountess is that Diane Gaston takes the ingredients of what could have been a highly readable road romance – an unusual plot, a delicious hero, the original setting – and spoils them by clinging to a heroine who after a fairly promising beginning goes into the sort of utterly conventional secretive, self-sacrifical and TSTL mode one sees all too often in romance heroines. The bones of a good romance are here – an alternative plotline that with only one major change would have permitted Marlena to act as a woman of sense sticks out a mile –, but Diane Gaston doesn’t deliver that good romance. If you are interested in her books, I recommend you read the much better The Mysterious Miss M or The Wagering Widow, and give this one a pass.