Dublin, 1742 When young and beautiful Mary Molesworth is forced to marry Robert Rochfort, widowed heir to an earldom, she finds her love is not returned. Jealous, cruel and manipulative, Robert ignores her after she has provided him with a male heir, preferring to spend his nights with his mistress. Power-hungry, Robert builds up a reputation that sees him reach for the highest positions in the land. Caught in an unhappy marriage, Mary grows closer to Robert's brother, Arthur. Acknowledging their love for each other, they will risk everything to be together. But Robert's revenge threatens their lives and tears them apart. Will Mary and Arthur find a way to escape Robert's clutches? Based on real events, Heart of Stone is a tale of power, jealousy, imprisonment, and love, set in 1740s Ireland.