Affair by Amanda Quick

Charlotte Arkendale knew all there was to know about men. After all, she'd made a career out of steering marriage minded women away from untrustworthy members of the opposite sex. Yet nothing could have prepared her for Baster St. Ives - an arresting stranger too daring, too determined, too dangerous to be her new man-of-affairs. Still, perhaps he was the perfect person to help Charlottes investigate the recent murder of one of her clients. So she gave him a chance, never realising that Bacter, a gifted scientist, would soon conduct a risky exploration into the alchemy of desire, with Charlotte as his subkect. But even as he sets out to seduce Charlotte, a twisted killer lies in wait, ready to part the lovers, or see them joined forever - in death.