When Julia, Lady Fieldhurst, returns from Scotland restless and out of sorts, her friend Emily Dunnington plans a select dinner party with half a dozen male guests from whom Julia may choose a lover. But Emily's dinner ends in disaster when one of her guests, Sir Reginald Montague, is shot dead. When Bow Street Runner John Pickett is summoned to Emily's house, he is faced with the awkward task of informing Lady Fieldhurst that their recent masquerade as a married couple (Family Plot) has resulted in their being legally wed. Beset by distractions--including the humiliating annulment procedure and the flattering attentions of Lady Dunnington's pretty young housemaid--Pickett must find the killer of a man whom everyone has reason to want dead.