Years ago, Emily's childhood nemesis, Emma Callum, scandalized polite society when she eloped with an Italian count. But now her father-in-law lies murdered, and her husband has fled, making him the prime suspect. Alone in her empty palazzo, there's no one Emma can turn to for help but Emily, who leaves at once for Venice. When a 15th century ring is found in the hand of the slain man, the mysteries of the past and present become entwined, and in order to find the murderer, Emily must first unravel the secret of a centuries old love affair. Her investigations take her through the canals of the ancient city, from opulent palazzi to slums, libraries, and bordellos, but the past does not give up its secrets easily, especially when these revelations might threaten the interests of some very powerful people, and Emily finds herself stalked by an ominous masked figure, determined to keep her from solving the case at any cost.