Confounding Oaths By Alexis Hall

A nobleman must work with a dashing soldier to save his sister from a mystical bargain gone wrong, diving into a world of malicious fey, enigmatic cults, and treacherous magic in this irresistible romance from the bestselling author of Boyfriend Material.

The year is 1815, and Mr. John Caesar is determined to orchestrate a successful coming-out for his younger sister, Mary. Despite his best efforts, he is thwarted by the various interventions of a ragtag regiment of soldiers, a mysterious military cult, and a malicious fairy godmother.

When Mary is cursed by the fair folk, the dandyish Mr. Caesar is forced to work with the stolidly working-class—yet inescapably heroic—Captain James to rescue her. While Mr. Caesar is no stranger to dallying with soldiers, until now he’s never expected one to stay. Or wanted one to. But even if the captain felt the same, there’d be no chance of anything lasting between them. After all, he and Mr. Caesar come from different worlds.

And lately, other worlds are the last thing either of them want to be dealing with . .