Highland Alliances Series by Terri Brisbin

She’s the best wife......he never wanted!Ross MacMillan lifts his bride’s veil…and discovers it’s not the woman he’d agreed to marry but her beautiful younger sister, Ilysa MacDonnell! The new MacMillan chieftain must accept Ilysa as his wife, for retaining his clan’s lands depends on her father’s support. But why is she there? Are her aims to help him or her father? Drawing out Ilysa’s secrets will kindle an alliance more powerful—and passionate!—than Ross ever imagined…