The Duke Effect (Rogue Files)

Despite being surrounded by her happily wed sisters, Nora Langley prefers botany to ballrooms and would rather spend a lifetime in her laboratory than consider affairs of the heart. An expert herbalist, Nora has been masquerading as her late physician father for years, dispensing invaluable medical advice. She corresponds with people all over the world, including an old army colonel. But when the man shows up on her doorstep, he is nothing like she expected—he is a young, handsome heir to a dukedom who suddenly threatens everything she holds dear.

Constantine Sinclair arrives on the Langley doorstep in a desperate bid to save the woman who raised him, the Duchess of Birchwood … only to discover that the venerable doctor he expected is a bold and lovely charlatan. Furious at the deception, he vows to reveal her secrets. Determined to prove her skills, Nora promises to save the duchess in exchange for Con keeping her secret. Con reluctantly agrees… and soon Nora’s brilliant, headstrong ways are throwing his carefully controlled life into chaos. What happens when the rigid soldier begins to lose his grip on his heart?