As far as London's high society knows, Lady Isabel Morrow is above reproach. But the truth is rarely so simple. Though the young widow's passionate fling with dashing Bow Street Runner Callum Jenks ended amicably months ago, she now needs his expertise. It seems Isabel's late husband, a respected art dealer, was peddling forgeries. If those misdeeds are revealed, the marriage prospects of his younger cousin--now Isabel's ward--will be ruined. For the second time, Isabel has upended Callum's well-ordered world. He's resolved to help her secretly replace the forgeries with the real masterpieces, as a... friend. A proper sort of friend doesn't burn with desire, of course, or steal kisses on twilight errands. Or draw a willing lady into one passionate encounter after another. Isabel's scheme is testing Callum's heart as well as his loyalties. But with pleasure so intoxicating, the real crime would be to resist...