Effervescent bon vivant Lucy Eastlake is a young operetta singer whose star is on the rise in Edwardian London. Though struggling to maintain her beloved great-aunts' household, she holds fast to the belief that “things will work out.” Now, with the fiftieth anniversary of a siege her great-aunt Lavinia lived through approaching, it looks like Lucy is right, because a fortune is due to be divided among the survivors. All Lucy and her great-aunts have to do is travel to a small Pyrenees town to claim Lavinia's share of a fabulous treasure in rubies. What could be more simple?

Professor Ptolemy Archibald Grant is the brilliant, straitlaced grandson of a British lord who also withstood the siege. When his grandfather asks him as a matter of honor to escort his old love on the journey, the about-to-be married professor agrees, not expecting Lucy to be part of the bargain. Losing the great-aunts en route, the handsome, buttoned-down professor finds himself caught up in Lucy's quirky, bewildering, and probably illegal efforts to reunite with them, as he is drawn further and further into an inexplicable infatuation with the free-spirited singer. What could be more complicated?

But when unwilling attraction gives way to sizzling passion, both will be forced to confront the ages-old question of whether love trumps honor…or the other way around.