An unlikely pair finds love in the shadows of the 1893 Chicago World’s Fair.
Ever since the death of her father, Lydia Bancroft and her mother have struggled to survive, their place in society endangered unless Lydia can make an advantageous marriage. Lydia’s become intrigued by a handsome man who often comes to sit and read at the library where she works, though he never speaks. The man is Sebastian Marks, who rose from dire poverty to great wealth. Now he owns the Silver Grotto, a popular gambling club, and lives in a suite in a hotel. He’s been so intent on reading to improve himself that it would be hard to tell he wasn't born a gentleman. Neither Lydia nor her fiance, Jason Avondale, knows that the person they must marry for money has none. Taking Lydia to tea at Sebastian’s hotel, Jason physically hurts her when he realizes she knows Sebastian, a man he hates because he owes him large gambling debts. After coming to Lydia’s aid, Sebastian slowly builds a relationship with her, even providing her with a maid when he realizes she’s selling all her family’s valuables to keep food on the table. Lydia naively begs him to take her to see the Silver Grotto. When Jason is found stabbed to death on the doorstep, they’re both prime suspects.
The last in Grey’s Chicago World’s Fair mysteries (Deception on Sable Hill, 2015, etc.) uses an anemic mystery and a far-fetched love story to explore her continuing theme of mismatched couples.