When the plague of 1680 decimates Prague, Ilona’s comfortable life as a wealthy merchant’s daughter is thrown into chaos. Her best chance of survival is a hastily arranged marriage to Lord Josef of Ivštejn, a decaying castle hidden deep within the forests of Bohemia. But when he tragically dies before their wedding, and is replaced by his abhorrent Uncle Wilhelm, Ilona knows that whatever evil angels decided her fate must have condemned her to a life spent in suffering.

Then, one midwinter night, she encounters the ghost of Josef—and he is clearly a more perfect match for her than she could have dreamed. As the two fall in love, Ilona must draw on whatever power she can conjure to bind Josef to her and escape her doomed marriage to Wilhelm.

But as Ilona pieces together the nature of Josef's existence, it becomes clear that his soul is tied to a darker history than he has led her to believe. When she realizes that she may have already fallen too far into the infernal underworld that Josef has opened to her, Ilona must decide: should she retreat into a life of quiet misery? Or honor true love at the cost of her soul?