The Gentleman and His Vowsmith

BRIDGERTON WITH MAGIC AND MURDER!
Lord Nicholas Monterris is the only heir of Monterris Court, a crumbling manor house. Bored and trapped, Nic spends his days crafting new automatons and his nights enticing handsome rogues into his bed, fiercely ignoring the fact that one day he must marry to save his family from complete decline. One day comes swiftly when his father selects his intended, Lady Leaf Serral.
Tradition dictates the two families be locked in together while the marriage contract is magically drawn up, which Nic assumes will be the worst part. Until he learns the Serrals' head negotiator is Dashiell sa Vare, an old flame he has neither forgiven nor forgotten, a man their rigid class structure forbids him to love.
Locked in the moldering grandeur of Monterris Court, tension is thick and that's before the first dead body turns up. The second body seems to be a warning that someone doesn't want the contract to go ahead. As things become more precarious, Nic will have to team up with his former lover and his future bride to uncover the mastermind behind the murders before it's too late.