London, 1875. At Lady Cornford’s famous soiree (sugared almonds and tittle-tattle), everyone is gossiping about Henry Ellis Margam’s latest hit, The Widow’s Secret. Only a few people know that one of Lady C’s guests, the enigmatic Bella Wallis, is in fact the best-selling novelist. Bella punishes evil-doers by exposing them as thinly disguised characters in the books she writes under her male pseudonym. Armed with her pen, the handsome Miss Wallis surrounds herself with useful men: the dashing Philip Westland, possibly a government spy; Captain Quigley, Bella's fixer; and his shady assistant, Murch, who can always crack a bone or two when someone needs persuading.

Westland comes to Bella with a problem: his best friend, Kennett, is smitten by the heiress Miss Mary Skillane. But Mary’s father, Sir William is ‘an old fraud with a beautiful daughter’ and she has been promised to Robert Judd, a vulgar treasure seeker. Mary is due to inherit the Skillane pearls, currently residing in a red lacquer box in a Cornish bank vault. But the pearls it seems were ill-gotten, and as Bella and her band uncover more of the strange business, a new Henry Ellis Margam novel looks set to be written, if Bella can first side-step her own affairs of the heart, and evade a brutal threat to her life....