False Lady by Summer Hanford

In London, traders of innocents have grown brazen, abducting young women from streets and carriages to sell to the highest bidder. Madelina Graydrake has spent her life training to find and take out the ringleaders behind the abductions, but nothing prepared her for finding good in her prime target, Jasper Mclintock.
per Mclintock had everything before his father died. Once the favored son of a Duke, his bastard-status now relegates him to operate undercover on the fringe of society, saving stolen girls from London’s brothels. How much easier would his task be if bewitching socialite, Madelina Greydrake, a young woman far above his station, hadn’t stolen his attention?
In a society built on gossip and class, Madelina and Jasper will realize the secrets they seek to protect could well be the very things that destroy them.