Light and Shadow Vol. 1 (novel) - Light and Shadow, #1

A fallen kingdom. A forced marriage. A switched bride. When Duke Eli discovered that the woman sent to be his bride was a lowly maid instead of the noblewoman he was expecting, he was furious. Despite his reluctance, he agreed to the marriage to appease his king and prevent more bloodshed. However, Edna soon proved to be more than just a servant. With her boldness and quiet defiance, she challenges Eli in ways he never imagined possible. As they spend more time together, Eli realizes that there's something peculiar about Edna.
She knows the castle like the back of her hand even though she's only just arrived. As a result, Eli can't shake the feeling that Edna is keeping secrets from him-secrets that could not only shake the foundations of their marriage but change the course of the kingdom's history. As he struggles to uncover the truth, Eli finds himself torn between his duty and his growing feelings for Edna. Will he choose to honor his obligations to the kingdom, or will he risk everything for the woman he's come to love? The brightest lights cast the darkest shadows.