City of Mirth and Malice by Alexis L. Menard — book slip

Nicolai Attano has achieved his dreams: control over the Iron Saint Railway and safety for his family. But when his wife, Camilla Marchese, is kidnapped, he must strike a dangerous bargain to rescue her.

As Camilla struggles with her newfound powers and faces trials that could destroy her, the city of Lynchaven teeters on the brink of chaos.

Loyalties are tested, and time is running out in this action-packed conclusion to Nico and Milla's story.

For fans of Peaky Blinders and the Grishaverse.