The Casebook of Harriet George Books in Order

The Casebook of Harriet George takes place on an alternate Mars in 1815, a place where Regency manners share space with clockwork devices, strange landscapes, and dinosaurs. Tharsis City has elegant parties and strict social expectations, but the wider planet is full of air forests, deep valleys, and dangerous wilderness.

Harriet George is sixteen and not at all interested in the life her older sister has planned for her. She is expected to marry well and settle down, while Harriet wants something useful, exciting, and entirely her own. Fortunately, or unfortunately, trouble keeps turning up at her family's door.

Her closest partner is Bertrand, her brother-in-law and a police inspector who has not exactly built a reputation for catching criminals. Harriet is the sharper investigator, though Bertrand's official position gets them into places she could not reach alone. Their cases put the family's already shaky finances at risk, which means failure is never just embarrassing.

In The Dinosaur Hunters, Harriet gets involved when the famous jewel thief known as the Glass Phantom arrives on Mars. The trail leads to a dinosaur-hunting expedition and a mystery that becomes much more dangerous than a stolen gem. The novella introduces the series' mix of drawing-room concerns, detective puzzles, travel, and creatures that may decide people are lunch.

A Spy in the Deep moves Harriet into the British-Martian Intelligence Service. Her training has been less glamorous than she hoped, and her first proper assignment sends her with Bertrand to an underwater hotel. A murdered footman disrupts the mission, leaving Harriet to sort through secrets and suspects before the danger traps them below the surface.

These are compact mysteries with a lively, adventurous feel. Harriet is bright, stubborn, and still learning what she can do, while Bertrand brings good intentions and regular opportunities for chaos. The books work as individual cases, but reading in order lets you watch Harriet move from determined amateur detective toward the stranger and riskier work of a spy.