If a lady is to become a countess, there are rules.... Number one: A lady does not attempt to come out in London society disguised as her deceased half-sister. Number two: A lady does not become enamored of her guardian; even when his masterful kisses and whispered words of affection tempt her beyond all endurance.

When Lady Henley Killigrew's father dies and his title of earl passes to a not-so-friendly cousin who wants her and her two younger sisters out of their elegant London townhouse, she takes them to Moonstone Cottage, a lovely manor house they inherited from a maiden aunt in the Cornwall seaside village of Moonstone Landing. But their funds are limited, and the new earl is a stingy guardian who will not loosen the purse strings to allow her to properly maintain herself and her sisters in their new home. The only way to save them all is for her to marry.

When Lord Meriwell collapses and dies at his dining table, Barnaby and Penelope Adair are summoned, along with Inspector Basil Stokes, to discover who, how, and most importantly why someone very close to his lordship saw fit to poison him. When Lord Meriwell dies at his dining table, Nurse Veronica Haskell suspects foul play and notifies his lordship’s doctor, eminent Harley Street specialist Dr. David Sanderson. In turn, compelled by a need to protect Veronica who is at Meriwell Hall as David’s behest, David calls on his friends Barnaby and Penelope Adair for assistance.

Lady Emmaline Fitzhugh, a hopeless romantic, is tired of sitting with the wallflowers, waiting for her betrothed to come to his senses and marry her. When Emmaline reads one too many reports of his scandalous liaisons in the gossip rags, she takes matters into her own hands.

Tired of dealing with legalities relating to his father's unexpected death, new baronet Sir Philip Selbourne is ready to leave London and head home for Christmas. But having spent a boyhood rescuing strays, he's unable to resist helping a desperate young woman with speaking brown eyes and a kitten in her pocket.