London society knows Lady Isabel Morrow as a proper widow, the devoted guardian to a young ward since her art dealer husband's violent death. No one would guess that Isabel discovered his scandalous secrets—and coped by sharing a passionate night with Callum Jenks, the handsome Bow Street Runner investigating the case.

Callum couldn't forget the beautiful widow, but a grocer's son and a marquess's daughter inhabit different worlds. He plunges into the ceaseless grind of his work, never expecting to see Isabel again. Yet crime brings them together once more, as Isabel seeks Callum's help when another potential scandal threatens her ward's prospects. Her late husband's trade in forged art will become known unless a false Botticelli painting can be quickly swapped for a true one. And who better to help Isabel make the switch than the skilled Bow Street Runner who once won her trust . . . and a night in her arms?

A Runner cannot break the law, even when the law seems wrong. But an old loss and a twist of fate have Callum rethinking his loyalties—and soon enough, he agrees to aid Isabel. As they plan an art heist together, partnership turns to passion . . . and passion turns to love. Once their scheme has ended, can they build a life—or will their romance ignite the greatest scandal of all?