When mining baron Jackson Rushford coerces beautiful folklorist Mairey Faelyn into using her extensive knowledge to help him search for a map to a legendary deposit of ancient Celtic silver, she has no choice but to agree to the devil's bargain. The beastly man has already abducted her family's research library and installed it on his estate, threatening to hire a rival expert to find the Willowmoon Knot if she refuses. The Knot is the key to finding the treasure, and has been missing from her family's protection for centuries. The vast resources that Rushford offers to Mairey prove as irresistible as they are dangerous to her family's legacy. Trapped into 'helping' him, Mairey plots to lead the dark, thunderous 'dragon' astray at every turn.

But while adventuring together into dusty catacombs, castle towers, cozy country inns, even into the bowels of a coal mine, Mairey soon finds that Rushford has charming chinks in his armor, and guards his heart more strongly than any treasure. As their search draws them ever closer to the treasure, Mairey finds herself falling deeply for the man, fearing she'll be forced to betray either Jack or her pledge to her family. Is their love just a fairy tale, or will it last forever?