Wretched Mage by Juliana Pinheiro

Jane Darling thought taking over her family’s trade and attending a merchant fair would be her greatest challenge, until she stepped off at the wrong train station and was seized by a monstrous creature. When she realised she had unknowingly trespassed into the land of the mageborn, where magic and its people live in secrecy, it was already too late.

She is sentenced to remain there for a year under the watch of the loathsome lord of the estate, Reagan, only to discover he too is bound by a sentence from the same court that seeks to hold her captive. With her family’s livelihood at risk, Jane is determined to plot her escape, but leaving their territory can be a deadly task, especially for a human.

As she relies on Reagan to learn how to keep herself safe from monsters and violent mages, Jane realises his situation is far more dire than she believed. When a forbidden romance ignites between them, Jane begins to seek answers about Reagan’s fate. But he keeps secrets even from his own staff, and with his political enemies turning their attention to her, even the most tenacious and well-protected human might not survive long enough to see the end of her sentence.