Return to the post-industrial age magical Isle of Lynchaven for the action-packed conclusion of Nico and Milla's enemies-to-lovers story where their city--and love--is at stake.

Some debts are not so easily repaid--or forgiven.

Nicolai Attano has achieved everything he's ever wanted: full control over the Iron Saint Railway. Never did he imagine he'd want anything more than power--not until his wife, Camilla Marchese.

When Camilla is abducted, he'll do anything to get her back. But with a city that's been poisoned against him, he's forced to seek the aid of a disreputable black-market dealer to ensure his wife's rescue. Despite the cost being higher than ever, Nico doesn't think twice. The collateral? His life.

Meanwhile, Camilla fights to gain control over her newfound powers and save herself, if her magic doesn't destroy her first. The only light in the hellish prison and brutal trials her alchemist captor puts her through is the hope of once again seeing her family . . . and the husband who stole her heart.