London 1815. Newly widowed Lily Adler is returning to a society that frowns on independent women. At a ball thrown by her oldest friend, Lady Walter, she expects the scandal, gossip, and secrets. What she doesn't expect is the dead body in Lady Walter's garden. Lily overheard the man just minutes before he was shot: young, desperate, and attempting blackmail. But she's willing to leave the matter to the local constables - until Lord Walter bribes the investigating magistrate to drop the case. Stunned, Lily realizes she's the only one with the key to catching the killer.

Regency widow Lily Adler has finally settled into her new London life when her semi-estranged father arrives unexpectedly, intending to stay with her while he recovers from an illness. Hounded by his disapproval, Lily is drawn into spending time with Lady Wyatt, the new wife of an old family friend. Lily barely knows the woman, but she and her husband, Sir Charles, seem as happy as any newly married couple...until the morning Lily arrives to find the house in an uproar and Sir Charles dead.

As the city prepares to celebrate Queen Victoria's golden jubilee, Veronica Speedwell is marking a milestone of her own. After burying her spinster aunt, the orphaned Veronica is free to resume her world travels in pursuit of scientific inquiry - and the occasional romantic dalliance. As familiar with hunting butterflies as she is fending off admirers, Veronica wields her butterfly net and a hatpin with equal aplomb, and with her last connection to England gone, she intends to embark upon the journey of a lifetime.

Lady Augusta Colebrook, “Gus,” is determinedly unmarried, bored by society life, and tired of being dismissed at the age of forty-two. She and her twin sister, Julia, who is grieving her dead betrothed, need a distraction. One soon presents itself: to rescue their friend’s goddaughter, Caroline, from her violent husband. The sisters set out to Caroline’s country estate with a plan, but their carriage is accosted by a highwayman. In the scuffle, Gus accidentally shoots and injures the ruffian, only to discover he is Lord Evan Belford, an acquaintance from their past.

England, 1865: Newspaper columnist Lady Katherine Bascomb finds herself the subject of speculation when her latest article leads to an arrest in the murders plaguing London. The English believe women ought not to write about such vulgar things as crime, and a particularly attractive detective inspector is incensed that she's interfered with his investigation. To escape her sudden notoriety, Katherine heads to the country - only to witness a murder upon her arrival.