The Shadows — Megan Chance

Grace Knox is about to turn seventeen, and the world of Victorian New York society should be opening to her―a time of dances and parties and boys vying for her heart and her hand. Instead, Grace's world is closing in: the family business is gone; her brother is drinking and gambling away whatever is left; her widowed mother cannot cope; and her grandmother is slipping into madness. And now Grace is having disturbing dreams of ancient battles.

Grace's only hope is to marry Patrick Devlin and let his fortune save them all. But she isn't sure she loves Patrick, and she doesn't share his passion to free Ireland from British rule. Why look to Ireland when there is so much poverty and despair here?

Then Grace meets Diarmid, an Irish stableboy. Being with him means losing everything. But the secrets and mystery surrounding him are too compelling to ignore. Soon Grace is drawn into his world of legend and heroes, magic and prophecy―the world of her dreams―where her own choice between faith and fear holds the greatest power of all.