Twenty-six-year-old Beatrice Hyde-Clare is far too shy to investigate the suspicious death of a fellow guest in the Lake District. A spinster who lives on the sufferance of her relatives, she would certainly not presume to search the rooms of her host's son and his friend looking for evidence. Reared in the twin virtues of deference and docility, she would absolutely never think to question the imperious Duke of Kesgrave about anything, let alone how he chose to represent the incident to the local constable. And yet that's exactly what she does.

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.

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.

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.

India Steele is desperate. Her father is dead, her fiancé took her inheritance, and no one will employ her, despite years working for her watchmaker father. Indeed, the other London watchmakers seem frightened of her. Alone, poor, and at the end of her tether, India takes employment with the only person who’ll accept her–an enigmatic and mysterious man from America. A man who possesses a strange watch that rejuvenates him when he’s ill.