She’s a duke’s daughter with a dagger beneath her skirts. He’s a rogue entrusted with her safety. And neither expected desire to become their greatest danger.

Lady Isabella Kingsley has never been content with embroidery hoops and tea trays. Sharp-tongued, dagger-trained, and unrepentantly defiant, she prefers pistols to poetry and would rather storm into danger than be shielded from it. But when her younger sister vanishes under suspicious circumstances, Isabella’s world shifts. The scandal alone could ruin them—but Isabella is determined to uncover the truth, even if it means placing her reputation on the line.

Enter Mr. Alistair Baston—her father’s enigmatic man of affairs. With his roguish smirk, too-handsome face, and secrets darker than a London alley, he is everything Isabella detests in a man. And yet, he is the only one her father trusts to keep her safe as they race through countryside hideaways in search of her missing sister.

The rules of propriety were never meant for a woman like Isabella. And Alistair has never known a lady so maddeningly capable—or so temptingly off-limits. As danger mounts and their forced proximity ignites into passion, the battle between duty and desire threatens to consume them both.

But when the trail leads to a truth more devastating than either expected, Isabella must decide what she’s willing to sacrifice: her heart, her honor, or the one man who dared to protect her—even from herself.

A Protector’s Promise is a swoon-worthy, slow-burn Regency romance full of scandal, longing, and unexpected love.