The Lyon’s Proxy Duke by Mihwa Lee

She bought a husband to secure her freedom. He came to collect.

Eleanor Sinclair has built her independence brick by brick, transforming from a grieving widow into London’s most formidable businesswoman. When her scheming executor threatens to strip away everything she’s fought for, she makes a devil’s bargain—a proxy marriage to an absent duke who promises to stay conveniently abroad. But her carefully ordered world shatters when Damien Westmore appears in her drawing room, drinking her brandy with insufferable confidence and no intention of leaving. Now the man she married for protection wants to claim his wife, and Eleanor discovers that her greatest threat isn’t losing her fortune—it’s losing her heart to the one person who has no intention of staying.

Three years of hunting through opium dens and foreign ports have left Damien Westmore hollowed out and desperate. When his brother vanishes back into the London underworld that had nearly killed him, Damien abandons his exile to reclaim the one weapon that can save them both—his proxy wife’s connections and wealth. But Eleanor isn’t the aging widow he expected; she’s a brilliant, beautiful woman who challenges him at every turn and makes him burn with desire he can’t afford to feel. As a deadly enemy closes in on everything they hold dear, Damien must choose between the brother he’s spent years protecting and the wife who’s become his salvation.