Betraying Season by Marissa Doyle (Published by Henry Holt, September 29, 2009)
Penelope (Pen) Leland has come to Ireland to study magic and prove to herself that she is as good a witch as her twin sister, Persy. But when the dashing Niall Keating begins to pay her court, she can’t help being distracted from her studies. Little does Pen know, Niall is acting upon orders from his sorceress mother. And although it starts as a sham, Niall actually falls deeply in love with Pen, and she with him. But even if he halts his mother’s evil plan, will Pen be able to forgive him for trying to seduce her into a plot? And what of Pen’s magic, which seems to be increasingly powerful?
I *loved* Marissa Doyle's first book, Bewitching Season, which was about Pen's twin sister. I wish this book was coming out sooner, I can't wait to read it! September seems so far away. :(