This book is a great example of the new genre called “romantasy.” Books given this label often seem to be standard romance with a random bit of fantasy thoughtlessly thrown in. But The Gentleman and His Vowsmith has excellent world-building and an interesting magical system. The romantic relationship is fraught, and obstructed by both magic and society. This is romance and fantasy at its best. And, for added fun, both the gentleman and his vowsmith are men.

In the tradition of romance, Lord Nicholas Monterris is the somewhat useless and extremely unhappy heir to a dukedom. He has been in love since he was at school with Dashiell sa Vere, who is—also a genre tradition—not a suitable match because of his lack of noble birth. (Their sexuality is a bit less of a problem.) At school, they both received training in the magic art of vowsmithing, the crafting of the intricate and deathly binding contracts that both empower the nobility and keep them in their roles. Dashiell finished his training; Nicholas did not.

All the story needs now is a new obstruction, which comes in the form of an arranged marriage for Nicholas to Lady Leaf Serral. Even this could be weathered, since Lady Leaf is a delightfully practical woman who has no more desire for Nicholas than he does for her. But vowsmithing the magical marriage contract between them requires weeks of locked-room negotiations. These must be attended by both families and their vowsmiths, with dire consequences for withdrawal. And, of course, one of the vowsmiths responsible for crafting this contract is Dashiell sa Vere.

Things get complicated very quickly, when Nicholas and Dashiell find a dead body at the bottom of the stairs on the way back from an ill-advised tryst. An accident, perhaps. Then ghosts begin interrupting meals and the suspicion arises that Lord Monterris, Nicholas’ father, is keeping dire secrets. Dashiell makes his way to Nicholas’ bedroom and, though Lady Leaf cheerfully accepts their relationship, not everyone is happy about it. Tempers get short. Then the murders start.

What follows is a genre-crossing delight of fantasy, romance, and mystery. It’s all there. Was it murder or accident? Why did Nicholas and Dashiell break up? What happened to the Monterris family fortune? Does someone (besides Leaf and Nicholas and maybe Dashiell) want to stop the marriage? And, of course, what will it take for Dashiell and Nicholas to find happiness together?