Joan Aiken continues her Wolves Chronicles with Black Hearts in Battersea, a tale of intrigue and treason, featuring Simon the foundling who helped Bonnie and Sylvia Green in The Wolves of Willoughby Chase.

Simon arrives in London ready to share quarters with Dr. Gabriel Field, also introduced in the previous book, and to attend art school. Much to his surprise, when he arrives at Dr. Field's new lodgings, he finds that his friend has vanished without a trace. Indeed, the peculiar Twite family from whom the doctor supposedly rented his rooms deny all knowledge of him.

Puzzled, Simon rents the rooms in hopes that Dr. Field will return, finds a job, and starts his art studies. He is delighted to find Sophie, a dear friend from his poor farm days, serving as an attendant to the Duchess of Battersea. In time, he comes to know both the duke and the duchess as well as Justin, Lord Bakerloo, the duke's nephew and heir, among others.

His oddest friendship, though, is with Dido Twite, the youngest member of the Twite household, who, although at first a nuisance and a brat, demonstrates pluck and resourcefulness when Simon stumbles across a plot to displace King James III with the Hanoverian pretender, Bonnie Prince Georgie. Yes, you read that right. Aiken's novel is set during an alternate history in which the Hanoverian line did not succeed to the throne.

Of course, the tale is melodramatic, featuring hot air balloon rides, marooned prisoners, a life-saving tapestry, shipwrecks and long lost heirs. Humor runs throughout the book but is well controlled and has substance. The characters are appealing or appalling, depending on the individual, and the characterizations are well-rounded within their melodramatic roles, particularly the feisty and courageous Dido Twite.

The narrative is more complex than The Wolves of Willoughby Chase which has a much more linear plot, and Aiken keeps the reader guessing all along. Narrow and hair-raising escapes abound -- sometimes at the same time -- and the unknown fate of Dido adds a note of seriousness to the tale. Overall, Aiken invests the novel with a tongue-in-cheek twinkle.

Black Hearts in Battersea is sure to whet the reader's appetite for more -- and there is plenty more adventure ahead.