In the hunt for relics of infinite value, perhaps the greatest treasure of all is family. Three months after the birth of his son, Miles Lawrence Hawkins, the fifth Earl of Archewyne, is attempting to acclimate to fatherhood, but he longs for adventure. Someone is masquerading as the heir to a powerful and ancient ducal title with the anonymous backing of other members of the ton, and Miles is asked to investigate. It would mean leaving his wife and child, yet he refuses to return to London without them. Emmaline Hawkins, the new Countess of Archewyne, is torn between wanting to be a good mother and wishing to recapture the excitement digging up relics and hunting treasures brings. Just as she thinks her adventuring days are over, she meets a young pawn broker questing after the legendary Lancelot Stone. Determined to retain the thrill of the chase, she stumbles upon solid proof the relic is in Paris, and convinces her husband they should investigate. As Miles and Emmaline chase shadows and investigate macabre sites, their steps are dogged by unsavory characters. The closer they move toward unmasking the duke's imposter heir as well as finding the fabled relic, the bolder a killer grows in attempts on their lives. As an unbelievable plot unfolds, their only recourse is to fight, side by side, and hope that leaving staid domesticity behind was the right choice.